Taiko no Tatsujin: 7-tsu no Shima is turning into the Love Boat of DS rhythm games: a massive confluence of guest stars at various levels of notoriety. Also, much like The Love Boat, the music is great.
Not only will Doraemon, the Oshiri Kajiri Mushi, and characters from Namco Bandai's own The Idolm@ster be popping in, but the seven titular islands will play host to even more game characters. Adorable little animate tiles from Mojipittan (a version of which is launching on WiiWare today) will dance, presumably to "Futari no Mojipittan," the game's signature tune. Characters from the horror/comedy manga (and, of course, DS game) GeGeGe no Kitarou spook it up, as do characters from the similarly gothy-cute Fukoumori. The Spelunker (of Spelunker) is no doubt happy to get a break from heights for a while.
Finally, yes, those are the Power Rangers -- sort of. Our Power Rangers have undergone countless team, costume, and even show changes, because the Japanese shows from which they use footage (pretty much everything in costume) change. The latest such Japanese show, and the one represented here, is Engine Sentai Go-Onger.