Really? Do you know of any companies that have admitted using Sketchup? Hadn't really heard anything at GDC the past few years (besides Google giving copies away at their booth).
I work at a major developer-publisher and we use Sketchup for mockups of levels. It's not part of the official level design pipeline but in the conception phase it's better than 2D sketches or plans. Also used: Lego and papercraft.
I don't know any that have talked about it in public but in general, companies are getting better at using off the shelf tools rather than building everything in house, if they can. Baby steps, but it's still progress.
