After adding the DOF preview Sony also added Mirror Lockup! This has been one of the most requested “features” by Sonyfolk! As you might remember we had a Sony MLU petition (SonyAlphaRumors supported the petition). I guess your pressure did the job and Sony did the great job listening to you!
Something else: See the Sony A55v “naked” at CNET Asia ;)
P.S.: Sounds like Kagoo has some A580 cameras in Store