Well, that didn’t take long 
With a few last minute fixes since Release Candidate 2, WordPress 2.7 “Coltrane” is officially released. This is probably one of the most ambitious releases to date, in particular due to the radically redesigned backend interface. [...]
WordPress 2.8.1 Coming Soon
Right on the heels of version 2.8, we will be seeing a WordPress 2.8.1 release soon. There are several minor bugfixes in so far, mostly dealing with tweaks to plugin and menu management. But the big problem driving a quick update is a bug in the core upgrade feature. It seems that in the case where the upgrade can’t be completed for some reason, the upgrade feature was deleting the wrong files when it attempted to clean up. Oops!
On the bright side, when this did happen, it would only delete files that are part of the core package, not any of your plugin or theme files. So the failure could be fixed pretty easily, by just manually re-installing the 2.7.1 or 2.8 files from a zip archive. [...]