Ubuntu actually released a netbook remix that would handle much better on something like this than the traditional GNOME desktop. Take a look: http://www.canonical.com/projects/ubuntu/unr
The iPad (and this tablet, for that matter) is not a netbook. Throwing Gnome without the bar on the bottom on it won't magically make Ubuntu usable on the tablet in any way that makes sense.
I can go compile an X server for the iPhone and run all of those apps on it as well (or, most of them. Some apps or their dependancies might do weird things with bits that may break). That doesn't mean that I will have a good experience using them.
These tablets are essentially netbooks that use a touch screen instead of a mouse. As such, I think that UNR would be pretty much just as usable on this as it would on a netbook.
I can go compile an X server for the iPhone and run all of those apps on it as well (or, most of them. Some apps or their dependancies might do weird things with bits that may break). That doesn't mean that I will have a good experience using them.