Right now I'm investigating the relationship between the Servant passages in Isaiah (chaps. 40-55) and Philippians 2. In Phil. 2, there is a part that says "he took on the morphe (form in classical Greek, status/rank/position in Koine/NT Greek) of a servant", which can be taken as a reference to the Isaianic servant. NT Wright brought this to my attention through his book, The Climax of the Covenant.
The way I'm going about it is to read the Isaiah passage non-Christologically. That is, I'm not reading it looking for possible references to Jesus. This is hard to do for a Christian raised in American exegetical circles, where everything is a reference either to the cross, the resurrection, or the second coming. In any case, I'm trying to read the passage as it would have been read when it was written, so that from there I might make some New Testament applications and, possibly, shed some light on the challenging Philippians 2 passage.
My first observations are that this passage (in Isaiah) is a poetic retelling of the whole story of Israel up to this point. You have God's calling of Israel to be His people, His promise of covenant blessing (which includes Israel's place as head of the nations), you have copious references to their failure to be God's light to the Gentiles, and you have constant reaffirmations of Israel's predestined role to fulfill God's purposes of bringing justice and shalom to the whole earth. All of this is set, at least the early chapters (I've only read to chap. 47 so far), in the context of an anti-idolatry trial, where YHWH God effectively steps from the dock to the judge's seat against the pagan gods. In the larger context, even, these false gods are primarily (but not exclusively) the pagan gods of Babylon who were to carry the servant away in exile (the even larger context starts in chap. 39 where Hezekiah foolishly shows all of Judah's treasures to the Babylonian emissaries).
Secondly, the use of imagery and themes from the Exodus is prevalent. The Servant is to be delivered from exile through another Exodus, so that "he" can complete "his" work.
Thirdly, I am interested in a provocative and potentially important (Christologically-speaking) passage in chap. 43. It reads "Fear not, for I am with you: I will bring your descendants from the east...[and all four directions--an image of the end of Exile]...everyone who is called by My name, whom I have created for My glory; I have formed him, yes, I have made him." Who is called by the Name of YHWH God! Who shares/is His glory! All of this predicated of the servant/people of Israel. I must read more...