As announced, we've begun the Media Code Sprint to put better media handling into Drupal core!
It's been a great time so far. In the morning, drewish compiled a file function guessing game (free beer!), and andreiashu took the bait and completed the first round with great feedback about how unusable the current state is.
Next, we've sat down and begun writing SimpleTests for the hook_file patch. This has been great fun for me personally; though drewish is an old hand at building tests, this is completely new for me. And to top it off, webchick, Queen of Drupal testing, dropped by our table and got involved!
Even the process of writing tests has been helpful; we found at least one case for validation that had been missed in the original patch, and drewish decided that file_scan_directory needed refactoring. (He's currently chasing other problems as well, and cursing about finding himself going down rabbit holes.)
There's more fun to be had for all! If you want a quick 15 minute task that everyone is qualified to do, go play the File API Function Guessing Game. If you want to do more, then ping me (aaronwinborn), drewish, or dopry at #drupal in IRC, or leave a comment here!