Good news, I guess: http://news.slashdot.org/story/14/02/28/1937251/broadcom-releases-source-for-graphics-stack-raspberry-pi-sets-bounty-for-port
I hope we'll be able to boot the pi without a non-free blob once the free version got released.
I didn't investigate this in much detail, but as far as I know, the other single board computers which can be used in freedom have major practicle disadvantages. For instance, running a 100% free operating system on the olinuxino is not easy since it has an exotic cpu architecture, so you can't just install debian.
