Considering that, my main blog is now back on WordPress.com, but I’m keeping a few self-hosted test blogs around so I can break things and learn without fear. I still learned quite a bit in just ten days, like how to have a similar setup to WordPress.com, working with caching, choosing a stats program, and how to work with Genericons (which you can do on WordPress.com with certain themes). I even helped fix two bugs in the Authy plugin.
As for the rest of you still on WordPress.org, if you use Jetpack, I submitted a few bug reports and feature requests you might like. One of those might even be my first patch one of these days.