As an interesting continued note to my post about Michael Dell, Fabián Rodríguez, a Senior Ubuntu Support Analyst at Canonical Ltd, is reporting that Ubuntu Linux will be Officially Supported by Dell Computers. Whether this support comes in the form of Canonical Support or in-house at Dell remains to be seen. My guess would be that Dell will be contracting with Canonical to provide the support.
Normally, I wouldn't do this, but "dude, I'm getting a Dell."
Update: DesktopLinux.com has more details, including the specific machines to come preinstalled and ship dates. Looks pretty solid to me.