Bought the Wii version the other day. First impressions: The total look and sound of the original is captured completely. They've done a very very good job on that, not changing everything because they know better, instead they sticked to the excellent original.
It's great to have so many new songs and also to find the originals there. The songs all sound great.
I only own one controller and the nunchuck and I have to say that this just doesn't work for this game. The nunchuck often doesn't register the shake. The cord between the two controllers also ruins the maracas feeling. Also, the Nunchuck lost connection to the controller every now and then, and this interrupts the game. Luckely, you can continue.
Started on the easy level and to my surprise the lower (green) circles were not used at all at this level. The game is very easy at this level, TOO easy for anyone who knows his way in the original version. I passed all the songs in easy with an A grade at first try.
The normal level is better already. I like the added dancing moves but some songs have too many of them.
The main thing is that the feeling of the Wii controllers is a lot different from the real maracas used on the DC version. Although these don't work perfect either (I don't own the original Sega's but I do have two sets one from each "compatible" manufacturer.) the feeling is a lot different.
Sometimes "shakes" seem to lag and then "get up" in pace and the game registers them as Good, but they feel out of beat. Can't really explain it.
I can't give it a final verdict before trying it with two controllers.
Also, to have two (or more) player fun, you'll need at least 3 extra controllers which nicely adds up to the cost of the game, but the same thing was true for the original.