"Oh, well this one came out of nowhere - a preview of Quake 4 is hitting the net, for subscribers of PC Gamer magazine that will be hitting the newsstands Sept 21. The game is based on the Doom 3 engine and is a sequel to Quake 2. In fact, it starts in on the action right after Quake 2 finished up. You can fight alongside other marines or on your own. I am so excited I can hardly
hold my nailgun straight..."
Source:
http://www.anandtech.com/news/shownews.aspx?i=22959