The rumor is he is up for a recurring role on Bones. Possibly as a new boss for Booth or a love interest for Cam or both. Note this is just a rumor but the person who told me this has a pretty good track on Richard.
Source: bearscubsfan from the boneyard.
Might be something interesting as Hart has worked with this guy before on Judging Amy. (BF)
ETA: Another interesting tidbit: Richard Burgi used to be on Desperate Housewives... could explain Hart & Stephen's previous tweets... Of course they could also be talking about the "Neighborhood" episode. (FM)
on DVD today at 
as well at