Yesterday Sony officially announced the new 35mm format (full frame) mirrorless cameras, the Alpha a7 (24MP) and a7r (36MP). Along with the cameras Sony also announced a few lenses to go along with the new system. The cameras use the NEX mount, from the earlier APS-C sized sensor cameras, but the earlier E-mount lenses will vignette when used on the new 35mm frame cameras. Sony has also released a mount adapter to allow for the use of Alpha mount lenses.
One thing that I am curious about is the camera to lens weight balance. I can just imagine how poorly balanced the FE 70-200mm F4, announced along side the cameras, will be for hand held shooting.
What kind of impact will these cameras have on full frame DSRLs? Not much at this point. The limited lens lineup makes these cameras unusable as a standalone system, so for most users they will likely be a second camera. That's a very niche market, so don't expect to see your local camera club flooded with these Alphas by the end of 2014. Long term, I could see them being the basis on which other, more successful, mirrorless full frame cameras could be designed. That said, I think Nikon and Canon would be better off keeping their current lens mounts, and removing the mirror. The focus on making small bodied cameras is getting overdone. Smaller bodies are nice for traveling, but I'll take my full sized DSLR over these Sony cameras any day of the week.