Gametable is old news though recently released. Its been talked about a lot right back to iCon 2007 no less. Theres a lot of chat about it on FUM but ill summarize the salient points.

1. Its a pay per month subscription type model which is the primary beef for just about everyone who has ever commented on it.
2. It uses these 3D tokens of which you cant build them yourself.
3. You actually have to pay extra on top of the monthly subs to get more tokens over and above the 2D ones.
4. All players 3D tokens are pooled for the session but if a player leaves for one week then his token goes away.
5. Nobody has ever seen a real wilderness screenie so far. Alright if you like dungeons.

( The details are not clear so I might have some errors in there ).

In terms of VTTs there are about 5 really good ones of which just a few are pretty popular and of them MapTool is the most popular because it is good and free. If MapTool declared that somehow they wanted to charge then I think things would be different. Of the 5 good ones I think all the others charge. Then there are some really popular not so graphical tools like (what is it ?) OpenRPG (?) plus another 30 something VTTs of some kind or another.

WotC is playing catchup and though they have money and legal IP on their side I think the game is over for as long as MapTool keep up the pressure. Traditionally WotC software has been rubbish but this looks better than previous outings.

Theres going to be some people who will use official stuff no matter what but methinks that you would need a hole in the head to want to use gametable - if not then expect a hole in the wallet at any rate.

I don't think that WotC really get that RPG's are predominantly a user generated concept. Its hard to monetize it beyond the core rule books. This is particularly true now that desktop software can make great maps, printers can print them and the write up to commercial standards and the internet allows you to deliver them to anyone on the planet.