After some tests...

OK, so, I quite fell in love with MeeGo 1.2. Unfortunately, their "Tablet" OS isn't ready for mainstream. Some things fail, some thing just don't work at all, but man do they have an understanding of what we (and by we, I mean I) want! Like Maemo before, they did a really good job at inventing new ways to interact with the device, of using screen estate, etc.
Anyway, I also wanted to try things (Ubuntu, Jolicloud (or JoliOS, as they made Jolicloud an online service, accessible via the browser).
So, Ubuntu went fine, but for some reason I wasn't able to access the BIOS while booting from any stick except the one with the recovery image dd'ed on it. Once I made changes in the BIOS (no quiet boot, try USB first) then I've been able to launch and install Ubuntu, fiddle with it, and reboot and install Jolicloud (/dev/sda1 swap (2Go), /dev/sda5 Ubuntu (6.5Go), /dev/sda6 JoliOS (6.5Go)). I already had a configured JoliOS account, so it installed automagically all my previous applications (VLC, OpenOffice etc.)
I disabled the installation of a boot loader with JoliOS, as I knew GRUB 2, installed by Ubuntu, would do the job. It did very well, a simple 'update-grub' picked up the newly installed JoliOS partition, and added it to the boot menu. It should be noted that on GRUB 2, the selection is done via the 'soft button' (near the blue led) of the WeTab; an USB keyboard will not be recognized (it hasn't been, in my tests).
I installed florence in Ubuntu, a virtual on-screen keyboard that works quite well. It might be a little small, but it's resizable, and customizable. All in all, a good choice.
I wasn't quite satisfied with JoliOS: by default, there's no on-screen keyboard installed, and the buttons are really small (Unity in Ubuntu does a great job for this). So, I formatted /dev/sda6 to reinstall MeeGo 1.2, found here. You'll find a downloadable .img of MeeGo, version 1.2.0.90, built May 17, 2011. Another version can be found here, built July 26, 2011, but I haven't tried it.
Besides, Intel dropped MeeGo today, to found Tizen. Tizen should be approximately the same thing, under another name. A first release should be made available Q1 2011.
So, what about you? What is / are your favorite(s) OS(s) on the WeTab, so far?