Well I am posting this from Firefox on Ubuntu, and just great does it look! Ubuntu 7.04 (Feisty Fawn) is pretty much rock solid so far, and out of the box works great.
I have my nvidia graphics, sound, SATA, file sharing, WINE all working great, and am slowly working through getting a bunch of old documents out of Access 2.0 and Word 2.0 formats and in to PDF, which sadly takes a Mac and a copy of Office 2004, though OpenOffice made a valiant attempt. In fact I ended up printing the old Word Docs into PDF from Mac Office, straight into a SAMBA share, so I can now grab the unformatted text if I really need it.
Anyway, Ubuntu 7.04 will ship on selected Dell machines as of Thursday 24th May 2007, but you can download it and try it for free from the link above. Go try it! You’ll be impressed!