First, the speaker in Isaiah 53 is Isaiah. Isaiah is not merely "reporting"; he is a thinking theologian who is delivering God's message in his own words. He is God's covenant emissary, prosecuting the covenant. He speaks for God, yet he is also of the people who are accused. Thus, his language sometimes identifies with God (e.g. "my servant," "I will alot him"; 53:11-12), and sometimes with Israel (e.g. "our griefs"; 53:4). It may even be that at times Isaiah speaks for the prophets of God collectively (e.g. "our message"; 53:1). The perspective of the speaker changes throughout the prophecy, but not the person.

It is erroneously argued by some scholars that the speaker in Isaiah 53 is the Gentiles. This cannot be for a couple good reasons. For one, Isaiah 53 begins by assuming that the speaker has delivered a redemptive message to Israel that has been rejected. The Gentiles never did this in the history of Israel prior to the engrafting of Gentiles into the church during the New Testament period. For another thing, the Gentiles in Isaiah 52:15 are to receive the redemptive message from the servant, and this is to be a message they have not previously heard/understood. If the Gentiles do not know/understand the message prior to hearing it from the servant, it cannot be that the Gentiles are the ones who preach that message ineffectively in Isaiah 53 (which seems to assume the same basic chronological setting, and not to present a significant temporal disjunction).

I note with some irony that if this typical Jewish interpretation were correct, it would provide the Jews with a compelling reason to listen to the Gentiles who preached to them regarding the redemptive message of Jesus that they currently reject.

Second, the servant is not explicitly Jesus. It is rather the messiah. Because Jesus is the messiah, this prophecy finds its fulfillment in him. But we could not have looked at Isaiah 53 and predicted what Jesus would be like or specifically what he was going to do. Earlier in Isaiah, the servant is explicitly Israel -- but God does not have just one servant. Moreover, the New Testament teaches that Jesus is Israel. He is the only one who keeps the covenant; he is a remnant of one. In any event, Isaiah 52 (esp. vv.14-15), which introduces Isaiah 53, precludes the possibility that Israel at large is the servant of this chapter because it contrasts the servant with Israel. Isaiah 53 itself also distinguishes between "my people" (Israel) and the servant. Whether or not Jesus is the messiah (which he is), the servant in this chapter is the messiah, not Israel at large.

These passages are not talking about Jesus specifically, though, but about the Messiah. Moreover, the "surprise" is not apparent to me. Rather, the question is a rhetorical device, the impact of which is: "No one has believed our message." Isaiah is not so much surprised that no one has believed as he is appalled that no one has believed.

The form lamo is generally used to refer to plural objects. But it is a mistake to assume from this that it must always refer to plural objects. For example, in Isaiah 44:15 (same author as Isaiah 53:8, you will note) it refers to the singular object "it," of which the antecedant noun is pesel, the singular noun for an idol or image. This is certainly a rarer use of the form, but sufficient to demonstrate that context and not merely quantitative analysis must determine the meaning of the form in any particular usage. I might add that if one were really so concerned about the singularity or plurality of this pronoun, it would seem that one ought also to be concerned about the singularity or plurality of the verbs associated with "servant," which are all singular, as is the pronominal suffix in "his generation" in this same verse. Even if one rejects my argument about use and context determining meaning, it still must be admitted that the grammatical weight of the evidence favors a singular reading. And given the previously established flexibility of lamo in Isaiah 44:15, it is in my opinion more reasonable to understand the servant to be singular. I add that the Septuagint, which was translated by Jews and not by Gentiles or Christians, takes lamo as singular when it translates the last portion of Isaiah 53:8 as echthe eis thanaton ("he was brought to death"). As a side note, the KJV does not always translate lamo as plural in other verses (e.g. Gen. 9:26; 9:27; Isa. 44:15 -- again, I did not look up every reference).