A Bitcoin address effectively can act as 2 factor authentication. If you remember posting a Bitcoin address then you could sign the address and provide that information to theymos. If the hacker has changed the post that contained the address, then theymos will likely be able to see the post history. Basically, check the post history or try to remember any time you posted an address and tell him about it and provide a signed message. Even if you have sent the address via personal message you can tell him about it and he'll be able to find it. I believe I remember reading a post by theymos years back that he will ignore any messages which do not contain the information described above.

Found the link: https://bitcointalk.org/index.php?topic=497545.0

Awesome. Follow the above link to the letter and wait patiently. I see you did this but posted it publicly and assume you did the same in the personal message to theymos. If that is the case you should just wait. Make sure that it's correct and has the information though. Wait a week and just message him again. He has many messages per week, and the inbox is rather messy and one message can easily be overlooked so sending him a reminder in a week should be okay.