I wonder if in 20 years people will be talking about making a virtual online game on a table top. Instead of making virtual table tops.
Actually, many manufacturers are racing to build flexible LCD's that can bend and some even roll up. That could be your battlemat - just plop it on the table and run Maptool to it - THAT WOULD ROCK!
Do a search in Google for Flexible LCD or Roll up LCD
When I was 20, they said that holographic technology was 10 years away. I am 37 now and it still isn't here yet
I actually wanted to go to school for that