Aaron Brazell was on close 'WordPress Watch' on Friendfeed last night and as early as midnight (Pacific), some had found the download and were upgrading to the latest version, released one month early, WorldPress 2.6 .
Aaron and has been following the development through the betas and to the first release candidate and is a great resource here.
Matt Mullenweg made the official announcement on the WordPress blog, and as I write this, WordPress 2.6 is now available from the front page of wordpress.org and also as a one-button update.
I did one a short time ago and it was seem less (Not this blog. which is on Google's Blogger platform).
This is a significant upgrade with numerous improvements and new features and has gone through an extensive trial of debugging.
Who's Tyner? McCoy Tyner, a jazz pianist that WordPress chose to honor with this release.