IGN are churning out the GTA articles this weekend, they've now compiled a decent history of GTA article - if you haven't read one of these before then I'd definitely recommend you doing so. It gives a nice overview of how the GTA games came about, and travels through right up to GTA IV. Of course there's no new information in there, but it's still an interesting read.
So if you're feeling nostalgic, give it a read. Also, today marks the one year anniversary of the first GTA IV trailer release, can you believe all that time has passed?