I was in a standard wheelchair in Vegas my last trip, and had no problems. All the staff I encountered were very good about it. I don't know where you're going to be playing, but if you have a choice you'd want to play in a room with widely spaced tables. I played at Harrah's and it was fine. I was able to make do at Mirage, but the lower sections is really too jammed up for wheelchairs/scooters. They accomodated me, but I was lucky enough to have the game I wanted to play on the edge of the room.

Other times when I've seen players in wheelchairs, the staff has made every effort to accomodate them.