Sigh. Grand Theft Auto IV has been getting all kinds of conflicting reports on its PC release date. I've heard December 2, 3, and 20 from various sources. Rockstar's Social Club TV website its December 2, so let's go with that, hm?
When the game launches, they say with it will come a video editor; if you're a member of the Rockstar Social Club, you can post your videos online, track the ones you've posted, and get in on special contests and video-based competitions. Once the game is out, you can confirm/link your Games for Windows LIVE Gamertag to your account and "get on your way to becoming the Cecil B Demille of Liberty City."
If you ask me, this is a great idea true to the spirit of Grand Theft Auto; half the fun I've long thought is hanging out with friends and outdoing each other in terms of how much craziness and/or humour you can create. So props to you Rockstar, not only for this, but for making the PC version of the game worthwhile (even if it is coming over six months later).
The company says these "Social-Club-TV-supported in-game video features" will be in many more Rockstar titles in the future.
There are four videos up on the website already which you can check out. Here's one of them, a personal favourite titled "Niko vs. Niko":