I really like this game a lot, they did a good job at nerfing a few of the over-powered characters, but also nerfed a few people who didn't need it (Ganondorf wtf...) But I'm really pumped about all the new characters, they are all pretty sweet.
I am however quite disappointed in the online play, it is slow as hell and limits you to only 2 minute battles, which are incredibly lame. I stopped playing online after 2 days.
The wiimote is horrible for this game so I highly recommend getting a gamecube controller is you want to compete.