Aria of Sorrow = excellence
Portrait of Ruin = excellence
Circle of the Moon = excellence
The original 3 for nes = excellence (save for 2 in some ways)
Curse of Darkness/Lament of Innocence = good
Of course, Castlevania 64 = terrible.
There's a good history of excellent 2d platforming glory there. I know Iga has been iffy (according to the most recent NP magazine interview with the guy) about approaching the Wii with a new Castlevania game. He doesn't want to make a game only to tack on some Wii controls.
...Which is good, because when the time comes they won't focus on making a game for the motion-sensitive controls, but make a great game for a great system, regardless of what control setup they use. I think that if they go 2d, they should utilize the Classic Controller. If they make another attempt at 3d (which this is a great system to do that on,) then they should attempt to implement some light usage of the Wii-specific controls.
Either way, this is one of the best franchises in gaming history, and it's debut on the Wii deserves to have a lot of thought and consideration.