Oooh, it's going to be a tough call between this and Moblin when they both get out there!
My boats in the Moblin dock at the moment, assuming i can run standard Linux apps and it's not just a glorified portal. Not that Jolicloud doesnt look impressive, i'm just a little disappointed thats its not a full blown OS.
Kind of looks like Cloud by gOS (see http://www.thinkgos.com/cloud/index.html). It says Cloud is both an app and an OS. I wonder how that would be different from using a minimalist desktop environment like TWM and autostarting Firefox and maybe a launch bar with links.
I'm more of a fan of Ubuntu/Deb over Fedora (just what I cut my teeth on in Linux), so it'll be a tough call. I do like quite a lot of Moblin's features, but it uses quite a lot of changes that mean packages will have to be ported from Fedora to Moblin, whereas it looks like Jolicloud might be able to tap into Ubuntu's huge repo's