Yes its tough, especially so since you are dealing with Bank of America.
If your Realtor is not giving you information its probably because she hasnt been given any information by the bank. Is she calling them weekly for updates?
If you were my clients I would recommend you keep looking for another home while you are waiting on their answer. If you find something you like, then you can withdraw your offer to purchase on the short sale. This has been a successful strategy for the young couple I have been working with. They will be closing on their home in 2 weeks! (Not the short sale home)