As always, when you upgrade your system to the latest version, some things work better, others worse.
Here's a list of things that I found (in general, I recommend installing Jaunty):
- wallpaper-tray disappeared
Hm, well, not exactly, it just changed to be an integrated panel applet, so just add it with Add to panel... on your top-panel.
- OpenOffice 3.x is so much faster now!
But, all my installed extensions disappeared and I have to reinstall all of them.
Moreover I got the error "Could not create Java implementation loader" when installing some extensions. To solve this problem just install the "openoffice.org-java-common" package.
- At the moment there are no hardware drivers for your video card, so 3D animations will likely not work at the beginning.
Update on 12/5/2009: compiz still is unstable, on two of my laptops, moreover, I can't create a dual-monitor setup with more than 2048x2048 like before.
- mail-notification suddenly opens sticky message boxes for each e-mail arrived. It doesn't use Ubuntu's new notification mechanism.
You can enable avant-window-managers notification area, so that problem is gone, but also the mentioned notification mechanism which is more beautiful.
- Synaptic now offers to show you a screenshot of an application before you install it, but there aren't so much available yet.
- Video playback of totem got a big boost! Now I can play HDTV movies on my laptop which wasn't possible before without stuttering.