Next BIG game after The Conudit would probably half to be Red Steel 2. The game looks amazing; gameplay looks absolutely superb from what videos I've seen.
However, the next game I'll be purchasing for Wii is Wii Sports Resort.
I'm really anxious to hear word of another Legend of Zelda title. Super Mario Galaxy 2, a StarFox title, and another Crystal Chronicles game are among others. Man, Echoes of Time really sucked.
Well, don't expect much. It's rare that Wii games feature decent online play, most of the time it's just a little slap-on that they put in to take up menu space. But I do agree with you, they should bring out some fresh online material to the console, I just doubt it'll happen.
The Conduit is exactly what you're looking for. Ignore the single player the multiplayer is worth it.
As for what I'm looking forward to its surprising nobody here has mentioned Little King's Story. That's definitely my next buy. Wii Sports Resort I'm iffy on.
After that probably Monster Hunter 3 and Red Steel 2 or No More Heroes (depending on reviews for the last two).
All the old franchises are great, but I kind of want to see something brand new. I want a game on the Wii that has a similar impact to Halo on the Xbox.