It's a game cube RPG and from what I've heard, did not sell very well (probably because it was on game cube) even though the reviews for the game has being prety good. I've only played it for few hours so far, but the fighting system was one of the best I've seeing. So if you have a Wii and is starving for a decent RPG, it really wouldn't hurt to pick this game up in the bargain bins (it's like $9 on half.com).
I thought it was a bland and predictable game. The card interface didn't add anything to turn based gameplay and in some cases held it back. I liked Skies of Arcadia and Tales of Symphonia better. Fire Emblem is great if you can find it.
Just bought Baten Kaitos for my brother for Christmas, actually. Seems pretty neat, just from the little I've seen him playing it. If you're into great battle systems, definitely give Arc the Lad: Twilight of the Spirits a shot. Easily my favorite battle system in an RPG, ever (excluding strategy-RPGs like Final Fantasy Tactics).
Baten Kaitos Origins > Baten Kaitos. Tales of Symphonia, Fire Emblem, and Paper Mario: the thousand year door are also awesome rpgs for the GC.
There were two Paper Marios for the N64 and Gamecube, so they probably decided mix it up for the Wii.
Ah yes... when I said I bought Baten Kaitos, I actually meant Baten Kaitos Origins. But the first one still worth playing though, eh?
The first one is okay. I found the story in that one lacking because of some pretty mediocre translation, but some people do prefer the first. And the battle system is unique, even if you do have to collect a bit. They were both made from the guys who made chrono cross fyi.