Gummornin'
There are two major lines of interpretation for the "Servant": it can be collective ("Israel," 41:8-9; 42:19; 43:10; 44:1f,21; 45:4; 48:20; 49:3), more specifically referring to the Exilic community which came to believe it had suffered for the sins of the whole nation (cf. already Jeremiah 24). Or individual, referring for instance to the specific fate of the author of 2nd Isaiah which, of course, we know very little about (52:11--53 is probably one of the latest additions to the collection). Those two lines are not mutually exclusive btw (the prophet may be depicted as representing his community).
Anyway, what the text clearly does is a theological interpretation of some historical suffering: the concept of vicarious suffering / death emerges. It will be used again in the apocalyptic part of Zechariah and in the Qumran community (about the "Teacher of righteousness"), long before the Christian application to Jesus.