First of all, I strongly doubt this to be what they are still keeping from us. Second of all, if they did do it I hope they would:
NOT use red/blue glasses - I simply can't see the 3d image correctly with these. I may need to get glasses to even out my eye vision but I'm sure many will have similar problems, plus the image just isn't of a high quality.
NOT attempt a VR headset - next to no chance of this happening anyway but would explain their not caring about HD output. The price alone throws this out I think but if they did make one cheap enough to sell for the console I don't see how it could be anything other then crap.
MAYBE use "shutter galsses" - not sure if that's the real name for them but these are the glasses that only allow one eye at a time to see the screen but blocking the other one out (so the screen alters every other frame between left eye and right eye outputs). This, from what I know about 3D displays, is probably the best option. It could be synced up wirelessly or through the controller attatchment so that probably wouldn't be an issue. I doubt this would be too expensive. The problems are: a virtual halfing of either framerate or graphical quality to render frames for each eye (something that wouldn't help a console rumored to be inferior power-wise already), possibly problematic eye problems from too slow of a "shutter" effect, and not everyone getting the highest effect from it possible (differences in vision and how peoples eyes react).
The problems also can arise with the fact that most TVs are I believe 50 and 60Hz (60 fps max) so the most you would percieve would be 30fps. I see this technology being more of something maybe the generation after the next may use. I believe around 2007 or 2008 the HDTVs coming out will be running at 120 fps and closer to the year 2010 I've heard TVs framerate will be up to 240. My point here is that once most TVs run at atleast 120 fps an acceptable every-other-eye rendering tech could run at a smooth 60fps. But who knows, maybe by this time VR glasses will be good enough and cheap enough to make it to a console.