I've just completed updating the plugin, and have released version 2.2. You should have already gotten the notice in your dashboard that it's available.
A critical issue was brought to my attention a few days ago regarding version 2.1 causing a fatal error with WordPress 3.5. I have reworked the code in version 2.2 to take care of that issue, and included support for WordPress 3.4 so that you can upgrade now and not lose functionality.
If you are running version 2.1 of the plugin, you must upgrade to version 2.2 before you upgrade your WordPress install to version 3.5, once it is released, in order to avoid the fatal error issue.
There have been significant changes made to the admin bar (now called the toolbar) since the last plugin release. The code has been rewritten to incorporate those changes, and some extra goodies added, such as removal of the WordPress logo menu, and better handling of different user scenarios in Multisite.
So please, go update the plugin now, along with any others you need to, so you're ready when WordPress 3.5 is released.