I've been literally salivating over the prospect of Stereoscopy being implemented in Sketchup for years now!
There's now a growing number of video cards (AND monitors) that are 3D enabled, and, heck, Both Maya, and Solidworks have supported Stereoscopy for ages now, and work well with appropriate NVidia cards/3D Glasses, etc.
There's also a nifty product called the "TrackIR4" which uses an infared camera atop your monitor to track 3 reflective dots on a headband. Sort of a poor-mans Mo-Cap. Designed mainly for (you GUESSED it!) 1st person shoot-em-up games and Flight Sims, so you can just use your head to look around naturally. It's been available for about 5 years now, and I remember they DO had an SDK available. Years back, I was wanting to see stereoscopic 3D in Zbrush and Sculptris - along with Head-Tracking it would be like having a REAL lump of clay to sculpt, right in front of you - The Zbrush people still aren't very interested (they still won't even get their act together for the Space Navigator either, siting "lack of user demand" in my last communications. Catch 22).
Apart from really helping to resolve things well without having to constantly rotate the view, it would add HUGELY to the "That is SOOO COOOL" factor when you do your presentations on the right big screen!
Since EVERY feature Film currently in production is now 3D (except for Arthouse films featuring gay cowboys eating pudding...), Google simply needs to perceive enough factors to "see" the potentially upcoming tipping point of this huge user-desire, and just implement it.
I think it's just a matter of time now. Though, I really really wish the future would hurry up for this particular thing to happen for Sketchup!
Can't Wait! (takes medication... calms down...).