First of all, I like the Arcade Fire -- they're pleasant, I enjoy the album, and the performance I saw of theirs last year was great. That's about the extent of it, though. I don't wear the album like a badge nor do I only listen to certain rock bands because some critic says its the cool thing to do or whatever. I like the album, but I do think it's a wee bit overrated.
SonOF, I agree that a lot of modern pop rock is beginning to sound somewhat inbred with the constant mimicking of groups like Joy Division, Wire, The Fall, etc etc -- but I really don't sense anything "retro" about the Arcade Fire. In fact, their originality is one of the reasons I really appreciate them. Face it, the album is pretty diverse in its sound and is difficult to pin down as being simply derivative. Perhaps you should give the album a closer listen, or at least point to the "retro" sounds or bands the group is "recycling."
*Back on topic, I got Ted Leo and The Pharmacists' album "Hearts of Oak," and it's pretty good so far.