A good Welsh friend of mine, who loves Wario Ware as much as I do, was fortunate enough to get it last week. His impressions have generally been favorable, though he has told me that it lacks the relative depth of Twisted or even the first Wario Ware. First of all, Crowns/Medals are gone, which is unfortunate. What's worse, though, is that there are few unlockables to be found--the same problem that Touched had. The multiplayer is also surprisingly limited, with just a "pass the controller" mode (which makes it impossible to play with the strap).
As for the microgames, he told me that they're basically brilliant, making innovative use of the Wii-mote. One shining example of this brilliance has you put the Wii-mote down on a flat surface. Then, when a ringing sound comes from the remote speaker, you have to pick up the "phone." The brilliance comes from levels 2 and 3, where loud noise will come from your TV speakers to prevent you from hearing the ringing. I honestly would have never thought to use the remote speaker in that way.
He did, however, say that there may be too much innovation. As with Touched, the developers basically found every possible way to utilize the controller, so he can't fathom there being a sequel that uses the Wii-mote alone. Although, now that I think about it, they could always make use of the nunchuck for any potential sequel.
Another thing to note--he's had the game for a week now and still hasn't been able to beat the Dancing Warios game on level 1. This, despite the fact that he's a DDR fanatic. Apparently it's much more strict with movements than Wario de Mambo was.
Also, the one thing he told me that convinced me to buy Wario Ware Smooth Moves: (spoiler) "It's a Wii, Wario!" No one does fanservice like R&D1.