four

http://iworkwithtech.com/pcgames/gtaiv
Take these with a grain of salt.
Typically Rockstar will give a lower expectation of system requirements than what the kids normally  cook up.
Minimum System Requirements for Mass Effect on the PC Operating System:
Windows XP or Vista
Processor:
2.4+GHZ Intel or 2.0+GHZ AMD
Memory:
1 Gigabyte Ram (XP)
2 Gigabyte Ram (Vista)
Video Card:
NVIDIA GeForce 6 series(6800GT or better)
ATI 1300XT or better (X1550, [...]

Take-Two Interactive reports:
Rockstar Games, a publishing label of Take-Two Interactive Software, Inc. (NASDAQ: TTWO), is proud to announce that Grand Theft Auto IV will be arriving on the PC on November 18th and 21st in North America and Europe, respectively.
“We are very excited to be releasing the PC version of Grand Theft Auto IV,” said [...]

Finally the clues start trickling out. As they do and have done for years.
These aren’t set in stone clues from Rockstar Games, but the clues I have found stay within the routine and system of Rockstar Games’ method of clues:
http://truxtertech.com/news/?p=164
http://truxtertech.com/news/?p=165
See the kids have gotten lazy and so Rockstar does not realize they are out there. [...]

It seems to be happening before the heathens can even play the game.
Funny this kid got mugged for his game, but he got it back.
These guys fight over a place in line.
See it’s idiots like these guys that make the media jump all over the place and blame the game makers because pattern keeps [...]

These guys have some idea that the world of gaming has rules that are written in the souls and blood of man.
I think the DLC can happen, just not the way they think it will.
Why else would the game have been delayed like it was?
Newbies!

Well if you have been wondering how it works and how it looks.
Let’s look at what IGN thinks about GTA IV

Well If you wondered when you will get your game, Don’t wonder… you will now know exactly when yours will show up on your door step.
Quoted from GTAFORUMS.COM
Hi guys I’m a big GTA fan and a long time lurker but today after my shift was over I just had to sign up and tell [...]

Some dude just farts around with the game. Looks like he has the game and is playing it.
Maybe he’s a beta tester?
Maybe he’s the son of someone big?
Could be a pirate - I do not know - but here is the feed.
But from the rag doll effects and how the assaulted ball up and gets [...]

I have doubts, but what the hell?
Here is a link where people are talking about where or how to locate an early release.
From what I understand, all early releases aren’t real, and loaded with brand new unidentified viruses.
Good luck scanning them.
Early GTA IV