The only instance I've seen of this so far, but it is interesting. Also nice to see they are using Windows 7.
https://twitter.com/corentin_lamy/status/370581323775090688/photo/1
Edit: The bigger news.
Looks like a confirmation that Dual Shock 4 controllers will work on PC.
EDIT2: People are reporting that this is not the case at the main Sony booth, but at others.