The a560/580 has Mirror Lockup!
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!
Source: http://forums.dpreview.com
Official Sony A560/A590 product specifications are available at Sony.net (click here to download the .pdf). Also the A33/A55 manual is available for download
Something else: See the Sony A55v “naked” at CNET Asia ;)
P.S.: Sounds like Kagoo has some A580 cameras in Store