Here's my take, formed mostly before the early March statement on how the N900 hardware will be one of the first things to run MeeGo at least in development, not necessarily as a release:

http://www.farbot.com/node/4542

That MeeGo post, however, gives me hope for the n900's longevity. That's important for me when considering whether I should jump to it or to another platform.

I have a n800 right now that I use mostly for listening to podcasts (panucci, gpodder), keeping todo lists (gpe todo), taking notes (leafnote), reading small reference PDFs, and email (claws-mail).