I expect this is where gen 9 or 10 consoles will go. Current research prototypes can actually read images out of your brain in real time. No, seriously: http://gizmodo.com/5843117/scientists-reconstruct-video-clips-from-brain-activity
Give that ten or twenty years to develop and it absolutely will be able to project images in.
Personally, I don't think I'd play an MMO with this until we understood what it could do to you. I expect no first world nation would allow a console which could fry your brain like SAO's could, and a lot of people (myself included) would have privacy concerns. This is not the kind of thing I'd early adopt, but I'm not an early adopter, anyway.
There is indeed such a thing as a legal secret, ya know.