According to IGNcube, sources at Nintendo of America are saying that Super Smash Bros 2 will be at E3 in playable form. In addition, the game is supposedly farther along than we thought and could be a launch title. The first game was a huge success. Nothing is really known about SSB2 at this time. If you want the low-down on what we (I) hope will be in the game check out the Ultra Smash Bros: Online Frenzy dream game special.

There is also a list of possible characters the PGC team has dreamt up.

Also, we here at PGC are hearing that a Game Boy Advance version is being heavily considered, though it would probably be just a port of the N64 version.