Found this over on DriverHeaven.
To: Rockstar North, Take-Two Interactive Software Inc.
We value the consoles very much, but feel left out if the GTA: Vice City game would not be released on the PC. Even all consoles together aren't sufficient for a game of GTA's magnitude.
The petiton's author, and surely many of the petition's signers too, are fans of the GTA genre from the beginning and dont want to miss out on the next chapter of this saga.
We hope you listen to our cries and release it on the PC soon. Don't dissapoint your fans!
So far, over 10500 people have signed... Add yours today!
News source: Sign Petition - GTA: Vice City for PC