Well, I think i'll just stick to GTA4 on the console, even though GTA's on the PC been fun, the multiplayer component on the PC version will undoubtedly suck because the people making/in charge of it are bastards.
Outcome a: Its made to work with console, this guarantees a large pool of players, but it will be marred with lots of problems connecting, browsing servers and hosting your own.
Outcome b: It does not work with the console version, which means very few servers since everyone is playing it on the console, the ingame browser will probably still suck (especially if its Gayspy), and.. well, its just bad.
In short: The end is nigh.