If you live in the US, MCM is an affiliated distributor with Element 14. They offer cases, and much more, including many of the products that will work with it simply for that fact. It's smart; they make no money off the Pi directly, but should make plenty of indirect profit (including shipping in some cases, but mostly from the sales of accessories.)
Raspbian is a very efficient Debian ARM_HF install. With the 512 MiB version, you should be able to handle a more standard ArmHF flavor of Debian; however I still recommend Raspbian as it is optimized for the Pi. It comes with LXDE natively, as well as programming environments and more.
The 512 MiB version could easily be used as a small/portable workstation; people have done a lot of really cool things with them. There's webservers running off of two of them and external harddrives, for instance. (One handles one set of operations, the other another. That's with the 256 MiB version though; now with 512 it'd be even better).
They're powerful for $35, but don't overestimate. You'll probably underestimate it, actually.
They also make great, inexpensive HTPCs. Retrogaming + Great HD streaming? Yes please.
I need to figure out a decent PERL repository that works with it, though; CPAN doesn't like Debian, or Debian doesn't like CPAN. Which sucks. I should also learn Python and figure out the differences, if any, present in QT vs cpp.
