Last Thursday, the WordPress core development team got together to discuss the upcoming version of WordPress. In this meeting, it was announced that WordPress 2.9 is now feature frozen meaning additional features would be postponed to the next branch. The first proposed release date of WordPress 2.9 was October 31st but that goal is not attainable. Instead, expect to see Beta 1 around October 31st with release candidates released during the month of November. Depending on what happens during the testing phase, we may see WordPress 2.9 stable released during the second half of November or early December.
Expect to see details regarding how to participate in the testing process show up on the WordPress development blog within the next week or so.