Hmm... doing something like this is very possible. I never played HeroQuest, though, so I don't know the rules are. Some of my friends had it, but I never got a chance to play.
But, I had a game called Dark World and it seems to be very similar.
I've thought about programming something like this for the web where the DM would set up a board and then the players would get to go and shit. Games would be password protected to participate but visible to the public, etc... I might start on it after I finish my current webgame.
For right now, wouldn't just an image of the game board that the GM updates in Photoshop suffice (Just scan in the board and splice it together)? I could code up a random dice roller in a few minutes for this.