If you can use BCI to play a video game, it's not such a big stretch to think of it providing control of, say, a virtual avatar - the name "Second Life" takes an altogether different meaning there. Being a software developer would, at any rate, definitely be handy in that situation.

BCI is intriguing, but from what I understand, it's not the best option at the moment - it's slower, more difficult, and less reliable than a gaze detector, which I assume would work in any case where there's enough muscle control to allow vision. At any rate, though, I know that those kinds of systems can be used in Second Life. I'm peripherally involved with Virtual Ability Island, which has members who use that kind of technology. And yes, virtual worlds (and Second Life in particular at the moment, though there are other options - OpenSim might be a slightly better option eventually for someone interested in open source) are uniquely useful for people with limited access to the real world.