Procrastinato on 04 December 2009
Okay guys, this may come as a shock, but... most large game studios, heck most game studios of all sizes, have *at least* one project in development that hasn't been announced.
Most titles aren't announced until they are at least halfway through their dev cycle, unless the hype train somehow needs an extra mile of track.
Every single studio you could name has a project you don't know about in development, I can say with 99% certainty.
