Connectivity is back: the question is, does it really add anything? The Pokemon Battle Revolution demo available at GDC seems to suggest that DS-Wii connectivity does little to truly enhance the gaming experience. The DS is used as a way of inputting your commands without your opponent having a look, but seemingly offers nothing else.
At least Pokemon Battle Revolution looks good: it easily trumps the two Coliseum games on the Gamecube visually (although that doesn't say much). Although I only played a non-localized Japanese version of the game, the cinematic presentation and incredibly enthusiastic announcer really added a nice touch of realism to the game. Certainly, Pokemaniacs will enjoy the game's highly animated character models: obviously, the Pokemon come to life in a way above and beyond anything the GBA or DS games will ever provide.
Without being able to see any single player component, it's hard to gauge if Battle Revolution will feature any gameplay "revolution." From the looks of it, the game appears to be quite a derivative product of the previous Coliseum games. However, considering the continued popularity of the franchise, maybe that's enough to satiate fans.