A reader sent me a detailed translation of the Sony invitation for the event in Hong Kong on August 28th (thanks Rebel):
"Released of new Alpha Cameras on Aug 28,
designed for photo enthusiast,
advanced technologies... superb DSLR functions... bla bla...
new Exmor CMOS sensor,
strength Quick AF Live View and high speed continuous shooting,
capture beautiful smiles,
share fantastic photos easily,
With new lenses, these cameras will bring exciting photographic experiences..."
Unless the translation is not accurate, we should expect more than one Sony α DSLR. They also mentioned a "new Exmor CMOS sensor". The "share fantastic photos easily" part smells like a built-in Wi-Fi. My bets are for α500, α550 and α850.