Bungie.net's new website now shows stats for both HALO 2 and HALO 3 games. It looks like there are quite a few people playing the HALO 3 beta.

A look at the HALO 3 stats:

386,601 Halo 3 Players (Last 24 Hours)
636,332 Halo 3 Games (Last 24 Hours)
19,763 Players Online in Halo 3

Compare that to:

171,485 Halo 2 Players (Last 24 Hours)
319,796 Halo 2 Games (Last 24 Hours)
6,000 Players Online in Halo 2

Goku says that over 100,000 HALO 3 players were online at one time last night. At the time of this post in the morning, 20,000 HALO 3 players are online compared to 6,000 HALO 2 players. Over twice as many HALO 3 games have been played in the last 24 hours than HALO 2 games.

It looks like HALO 3 is on track to be a successful game even with some matchmaking problems and a delay.