Simon ‘corecode’ Schubert is looking for more information on finite state automatons, since a number of them appear in the DragonFly source.
… but it’s still being worked on.
Porting SMBUS support from FreeBSD would be a good small project for anyone to try, though Jeroen Ruigrok/asmodai may beat you to it.
forknibbler.com now lists the DragonFly docs that are located there, including a PDF version of the Handbook.
Jeroen Ruigrok/asmodai has committed initial work to support Silicon Image 3112 and 3124 SATA controllers.