The good

Everything pretty much works without any configuration (the main reason to use Ubuntu as desktop)

• All notebook (Thinkpad X40) features working
• Logitech wireless keyboard, all the extra keys including multimedia keys are working and mapped correctly to the right applications.
• Proprietary stuff is supported. Granted, I can live without them, but Skype and Flash make things easier. The former with video is especial useful to stay in touch with family (kids) when apart.
• Packages are good for the desktop, on broadband a minute or two to get a missing application running.
• Proprietary multimedia codecs, popup dialog and click OK to install - very good.
• Printing all auto detected. Nice new printing setup dialogs.
• Numerous other stuff which just works with no configuration (stuff does what it should do).

The not so good

The new Intel xorg drivers have weird issues and a few quirks. They're all reported, so hopefully they will be fixed soon (at least we know 8.04 isn't too far away).

• Mirrored display when booting up to external display (luckily can close the lid).
• Screen remaining blank after going to sleep.
• Compiz doesn't quite work right with some applications, notably Evolution, have to turn it off. Expose plugin also not on by default (probably most useful one).
• SCIM default setting which causes browsers to randomly crash browsing CJK sites and input, is still on by default.
• MD5 mismatch for nonfree flash, have to do manual install, not exactly user friendly.
• nfs-client not in basic install

Yet to try

• Bluetooth support
• Suspend
• External display with projector
• Wacom tablet support (one of reasons to move to Linux on desktop)
• Fax with X40 modem + bluetooth phone

Overall impressions

I'm enjoying the use so far, except for the screen not resuming from power saving mode. I hope the link from ThinkWiki helps.

FOSS/Unix ~/. settings compatibility rock. I was able to get a working desktop within several minutes, by simply checking out my most important settings and folders from personal svn and continue where I left of. Whether I'm on FreeBSD or Linux (whichever distro) as long as application major versions are the same, I can move from one to another with basically all my most common settings and working files, simply by doing svn update. This is kinda of a mini version of the online desktop, where the main storage (svn) is in the cloud, but you can easily sync to work offline on your current desktop.