Not sure if it was mentioned here, but apparently the game had been presented at the
CDProjekt Spring 2010 Conference (which completely went under my radar, even though I'm from Poland).
There's a
photo of DTPs Claas Wolter showcasing it to the press in the
gallery (titled as "Claas Wolter prezentuje dziennikarzom grę Grey Matter").
Edit: Another shot
here, and
here's a short video interview with the man. Nothing new I guess, but some broken English from the interviewer at least.
It says in the comments that they were prohibited from filming the presentation, so that's a 'no video footage' I guess...