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.