Here’s what the next couple weeks are going to look like in terms of press events possibly related to DSLR announcements: Nikon goes first on August 19th, Sony does theirs on August 24th, and Canon has one scheduled August 26th. Nikon will likely be announcing the D3100, while Canon drops the 60D during theirs.
A big rumor regarding Sony’s upcoming unveiling is that they’re going to be showing us the world’s first pellicle mirror system on a DSLR camera. This means instead of a traditional bulky mirror that swings out of the way — as found in current DSLRs — the Sony DSLR will have an ultra-thin and ultra-lightweight semitransparent mirror that allows photos to be shot without the mirror swinging out the way.
One benefit is a higher number of frames per second and a shorter shutter lag — rumored to be 10fps — since the action of swinging the lens is eliminated from the equation. Another benefit is that the camera would be able to use phase detection autofocus while recording, since light can simultaneously be bounced to the autofocus sensors. Finally, no swinging mirror equals no viewfinder blackout when shooting, less vibration, and less noise — benefits also shared by rangefinder cameras.
sonyalpharumors reported in June that Sony is rumored to be releasing four new DSLRs to replace the A550: the A55 and A33 with pellicle mirrors, and the A560 and A580. Excited yet?
Update: Whoops. This is a private event where everyone will be signing non-disclosure agreements, so even if those attending are introduced to the camera, we might not hear about it for a while. The Nikon and Canon events should yield public announcements though. Sony might be planning to announce these things publicly at Photokina in late September.