GameSpy, IGN, and Lamespot have all just posted early hands-on previews of the PC version of San An. All their screenshots are the same, and they all say pretty much the same thing about the game, but with enough divergence in the info to warrant checking out all three. Gamespy, for instance, says that "mod tools should extend the game's life" in the header bit, which would seem to imply that R* will provide them. This seems highly unlikely, as one of the other articles pointed out. Also, IGN states rather confidently that R*^ won't be adding any multi-player support (then going on to place their faith in the ever-dodgy MTA mod). All three, however, seem to agree that the only new features (graphical goodness aside)will be the mp3 and replay features we've come to expect. Expect more info to begin flying in from all directions soon enough...
Thanks to davew2040, galamaheit 10 000, and Jordan for the heads up in this topic on the forums.