I'm a little bit miffed. The current official WP release version still is in its 2.9 cycle, yet some plugin authors have committed the otherwise laudable effort to update their plugin core so as to work with the upcoming 3.0 release. Due to the massive overhaul that 3.0 implies, that means many such WP 3.0 compatible plugins now actually require 3.0 - which by itself is understandable.
However, the problems begin when 3.0 isn't officially released yet, and those new plugin versions are pushed into the WP repository: the plugin update notifier nags you that a new plugin version is ready for download, so you dutifully upgrade the plugin and... KABOOM! Result: you have to dive in, delete the plugin manually, annoyance all over, and arguably frustrated plugin developers as well, as they have invested a lot of their precious time to prep for the new release.
It'd be better to implement a policy so that plugins that DEPEND on an upcoming WP release are NOT included in the repository.
Else, the security and stability reinforcing function of the plugin upgrade notification system becomes idleware: people simply ignore it. And then it's the opposite of helpful.
Sadly, the Ozh Admin Drop Down menu suffers from this issue; as much as I apreciate the plugin, I strongly object to releasing a new, beta-version of WP dependant plugin, and on the fly deprecate the plugin version that is compatible with the only current WP version.
In a sense, that's bad manners. Unintended, of course, but still.