The 4K Sony displayed this year at NAB show (Image courtesy: Engadget).
The swedish site Fotosidan reports the following info they got from Sony (Thanks Dennis for the translation!):
“More cameras on the way On the press meeting Yoshiyuki Nogama told us that a video-targeted system camera with A-mount is on the way/being developed. It shall compete with Canon EOS 5D Mk III and will have Ultra HD video (4K). We guess that this is a continuation of Sony a99. The Sony director also told us that further ahead Sony will launch a really fast full frame camera for action photography,”
This means Sony has not one but two A-mount cameras on roadmap!