I'm pretty sure this is already being worked on.
Give me a few minutes and I will find the PM someone received from theymos where he says that he is developing a system to automatically prove you own an account with your staked address.
How long will it take to be implemented? I hope that this system will work when the new bitcointalk forum has been launched. Sending PM thru theymos and Cyrus really eats a lot of time.