The first surprising thing about the Windows 7 beta is that it works great running in VMware, so if you have a relativly new vesion of VMware installed then it is well worth installing the beta to have a look.
The UI is distinctly vista like with the the round start buton and start menu, and similar dialogs, but for some reason it doesnt give off that hateful vibe that Vista does (having installed vista and immediatly removed it reverting back to trusty XP, Im no fan).
The beta comes with some nifty little apps like sticky notes and a great snipping tool for taking screen shots along with the usual games, calculator and of course paint (which is a nicely updated version in the vein of office 2007). It also comes with an IE 8 beta which may be of interest to some.
Overall i like the feel of Windows 7 and after seeing this beta I have high hopes of eventually upgrading my Windows XP machine to it.
So Microsoft, please dont f*$k it up before release.