Shiloh is definatly a person at least in that scripture, but is never menioned again in that context. Also it is rather strange that this said one Melchizedek is not talked about more. Its strange because Christ is coming in the Priestly Order of this man, this high priest Melchizedek, but we haven't been told exactly what that order was. The Levite priest Aaron never makes mention of a priesthood outside of Levi. But Melchizedek is reffered to as "the priest of the Most High God."
 For every high priest taken from among men is ordained for men in things pertaining to God, that he may offer both gifts and sacrifices for sins:
 Who can have compassion on the ignorant, and on them that are out of the way; for that he himself also is compassed with infirmity.
 And by reason hereof he ought, as for the people, so also for himself, to offer for sins.
 And no man taketh this honour unto himself, but he that is called of God, as was Aaron.
 So also Christ glorified not himself to be made an high priest; but he that said unto him, Thou art my Son, to day have I begotten thee.
 As he saith also in another place, Thou art a priest for ever after the order of Melchisedec.
 Who in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears unto him that was able to save him from death, and was heard in that he feared;
 Though he were a Son, yet learned he obedience by the things which he suffered;
 And being made perfect, he became the author of eternal salvation unto all them that obey him;
 Called of God an high priest after the order of Melchisedec.
 Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.
 For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat.
 For every one that useth milk is unskilful in the word of righteousness: for he is a babe.
 But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.
 Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God,
 Of the doctrine of baptisms, and of laying on of hands, and of resurrection of the dead, and of eternal judgment.
 And this will we do, if God permit.
 For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
 And have tasted the good word of God, and the powers of the world to come,
 If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
 For the earth which drinketh in the rain that cometh oft upon it, and bringeth forth herbs meet for them by whom it is dressed, receiveth blessing from God:
 But that which beareth thorns and briers is rejected, and is nigh unto cursing; whose end is to be burned.
 But, beloved, we are persuaded better things of you, and things that accompany salvation, though we thus speak.
 For God is not unrighteous to forget your work and labour of love, which ye have shewed toward his name, in that ye have ministered to the saints, and do minister.
 And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end:
 That ye be not slothful, but followers of them who through faith and patience inherit the promises.
 For when God made promise to Abraham, because he could swear by no greater, he sware by himself,
 Saying, Surely blessing I will bless thee, and multiplying I will multiply thee.
 And so, after he had patiently endured, he obtained the promise.
 For men verily swear by the greater: and an oath for confirmation is to them an end of all strife.
 Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath:
 That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us:
 Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil;
 Whither the forerunner is for us entered, even Jesus, made an high priest for ever after the order of Melchisedec.
 For this Melchisedec, king of Salem, priest of the most high God, who met Abraham returning from the slaughter of the kings, and blessed him;
 To whom also Abraham gave a tenth part of all; first being by interpretation King of righteousness, and after that also King of Salem, which is, King of peace;
 Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually.
 Now consider how great this man was, unto whom even the patriarch Abraham gave the tenth of the spoils.
 And verily they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law, that is, of their brethren, though they come out of the loins of Abraham:
 But he whose descent is not counted from them received tithes of Abraham, and blessed him that had the promises.
 And without all contradiction the less is blessed of the better.
 And here men that die receive tithes; but there he receiveth them, of whom it is witnessed that he liveth.
 And as I may so say, Levi also, who receiveth tithes, payed tithes in Abraham.
 For he was yet in the loins of his father, when Melchisedec met him.
 If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?
 For the priesthood being changed, there is made of necessity a change also of the law.
 For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar.
 For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.
 And it is yet far more evident: for that after the similitude of Melchisedec there ariseth another priest,
 Who is made, not after the law of a carnal commandment, but after the power of an endless life.
 For he testifieth, Thou art a priest for ever after the order of Melchisedec.
 For there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof.
 For the law made nothing perfect, but the bringing in of a better hope did; by the which we draw nigh unto God.
 And inasmuch as not without an oath he was made priest:
 (For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:)
 By so much was Jesus made a surety of a better testament.
 And they truly were many priests, because they were not suffered to continue by reason of death:
 But this man, because he continueth ever, hath an unchangeable priesthood.
 Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.
 For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens;
 Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people's: for this he did once, when he offered up himself.
 For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore.