I would be very surprised if the glasses worked correctly at all angles. Its quite likely it would be more immersive as 3d, but its unlikely to make a difference in online play. Offline play i'm sure you could be drawn into the game a lot better. At the end of the day you're still required to wear the glasses which is by far the biggest problem. The question is, would your average developer bother with such a thing?
Not work in online play? I'm sure Star Trek Online could be nice in 3D?

Would your average developer bother? I suspect it'll soon be so bound into DirectX that they'd hardly have to worry much about it... It's just be available almost as a side effect.