It's been long overdue, but the release of
uBar 0.9.4 implements
many new features 
and bug fixes. For instance, menus now close automatically when the mouse is clicked outside of the bar. Also, the width can be specified, either as a percentage or in pixels. A notable addition is the in-line search. Instead of popping up a box, the search function appears directly inside the bar (for bottom left/center/right positions only).
The best way to learn about the new features is to
try out uBar for yourself.
Upcoming Features
Integration with JoomFish is still in the works, along with MooTools 1.2 compatibility. Bookmarking, translation, and other "default" buttons will also be added to future releases. Other features are under review, such as an in-line login form and possibly a new bar position: top.