While I may not be a great fan of Dragon Ball...this has to be some of the best sprite animation I've seen in a long time. As well as that, its everything you could want in an opening sequence - while I may not have liked the background music, it was packed with action and really built up anticipation for whatever episode would follow the sequence...which is what you look for in a good opening sequence...also the length of the opening was appropriate..one of the worst things is if an opening is too long, destroys momentum and anticipation...but you didn't have a problem with that :P
Although it would have been nice if there was a replay button instead of a continuous loop...maybe that's asking for too much. In any case I'm sure this is gonna shape up to be an awesome series ;)