I just found an interesting UI glitch with Windows 7 RC.
If you drag the Taskbar to the left. Then extend it (drag it to the middle of the screen), then contract it, it leaves the remnants of the Taskbar over your screen.
There’s also a similar problem doing the same when the Taskbar is at the top of screen. Having it at the bottom (standard) and right sides are fine.
It’s for reasons like this that we have the RC, this will surely be fixed before it RTMs.
But what about the messy arrangement of icons if you extend the taskbar at the bottom of the screen ?