According to sources at Bjorn3d.com, QuakeCon 2004 will be holding first DOOM3 tournament.

"QuakeCon 2004 will be the hotspot for gaming this summer, with the first DOOM3 tournament being held at this years event. No date was set for the actual release of the game, but the tournament begins on August 12th, the first day of QuakeCon. The press release did state that the game is releasing this summer and that nobody will have had a chance to "practice or master the game."

And, sure enough, there was confirmation at the official site, with a full press release.

"For gamers, QuakeCon is the most exciting happening of the year, and this year it marks the arrival of DOOM 3 – which is one event we wouldn’t miss!"