The Quabbin is a cool spot with an interesting history for sure. I've heard that when the water is really low, you can see the steeple from one of the churches sticking out of the water. Not sure exactly where, and there are some spots that are restricted to fishing, so it may be in there. My uncle lived near there and he used to tell me about this local legend called Old Moses, which was supposedly a monster lake trout that cruised around the old villages underwater. Couldn't find anything on it though...
I do know you will probably want a boat to catch walleye, but you can rent them there. I think a lot of people troll for them. I went once with a buddy to fish for bass and there were a lot of people trolling. You can rent a boat there and they're pretty nice...high sides, plenty of room, I think it was like a 10 hp hand steer motor. Here's some info:
http://www.mass.gov/dcr/watersupply/watershed/quabfish.htm