Well the way OSS drivers developpment works means that you're far more likely to experience problems with new hardware than with old hardware. That, plus the mac pro, even if it is an intel based machine, is the most closed hardware you could find on this platform. So, "couldn't even" may not be the right choice of word for your situation .

I wasn't expecting it to work 100% flawlessly out of the box. But not even able to boot? I feel sorry for Canonical as 10.04 is an LTS release, so they're now stuck with this rather glaring incompatibility for years.

LTS versions have stable patch-level releases every 6 months while they're supported (e.g. 10.04.1 was released in July, and there will probably be a 10.04.2 in January), so they're able to add drivers to the installer when they become available.

Installing Ubuntu on a MacBook feels wrong. It was designed to run MacOS X. Even the chassis finish matches the window chrome...

In my interesting computer collection, I have a couple IBM PPC/POWER machines. When I acquired the first one, it took me some work to procure a set of AIX disks (DDS tapes would do) that would install on the machine. Several friends of mine suggested I should install Debian and be done with it, but I felt that would make them less interesting and opposed it. When I finally installed AIX, I felt they were complete, with the system they were designed to run, it all its CDE glory.

Last time I plugged a Mac keyboard on my Linux netbook, not even the function keys worked. It muted the speaker when I tried a search...