I'm sorry, having seen the previews for Bolt, I would have to say that the hamster in the ball has almost no similarities to Hamstard.
Point 1: Hamstard is probably the most cynical creature known to mankind. The hamster in the ball is probably one of the least cynical creatures known to man.
Point 2: Hamstard has never, save for one single comic, moved. That move was simply to go from full frontal to profile view.
Point 3: Hamstard does not own, use, or would even remotely consider using a ball as a method of transportation.
Yes, the one in the movie is rediculously overweight, just like Hamstard, but there the similarities cease.