Not sure if this counts as news or not, but Masahiro Sakurai wants to do something different from this new game. He doesn't want to just make a "bigger" Smash Bros. with new characters and stages, he wants something different. He hasn't exactly found that "hook" yet, though. More info:
http://wii.ign.com/articles/122/1223770p1.html
http://wii.ign.com/articles/122/1223770p1.html