I asked BitGo about how I would transfer my bitcoin if BitGo went out of business or was appropriated or hacked somehow. Basically your fucked. You have to use some convoluted way to move your bitcoin. I wasn't impressed when I found this out, and promptly moved my bitcoin. Until there is an easy way to move your bitcoin independently of BitGo, then their service isn't of much use.
Apparently you have to use this:
https://github.com/BitGo/BitGo-MultiSignature-Offline-Recovery-Tooltool requires all 3 keys.
if bitco have the time and ability to contact members, verify the members are who they are, and send the 2 service based keys to the user. then bitco can keep their server alive and just tell people to withdraw ASAP. if they cant afford a $10 domain fee per year. then i am starting to see flaws in the business model now..
the code for the tool thogh, could b used for the idea i mentioned a couple post back (signing a TX) and you also dont really need a bitcoinj either you just API it to the PUSHTx api's that some bitcoin services/mining pools have mentioned here:
https://bitcointalk.org/index.php?topic=318815.0