Currently there are a couple of
limits on creating the sorts of virtual worlds they have been talking
about:
Bandwidth - the Internet is still too slow for rich video
Time - who's going to program a virtual meadow with virtual deer?
We just don't have the way to do this with without immense amounts of
programming
Still, there are experimental educational virtual realities out there.
I'd like you to visit and explore TappedIn, an semi-graphical "world"
for educators to meet and communicate. You will be required to join, but
it's free.