I don't know. On one hand, the right kind marketing can sell any game. Not to mention that people sick of gimmicks may return. I'm not too sick of them, but I know there are people who are, so who knows?
On the other hand, there's always the issue of little to no marketing, and quite frankly, that may hurt its chances, gimmicks or not. It's a key factor here, and unfortunately, Nintendo doesn't seem keen on it, even if a game had something they could market with little to no trouble (like WarioWare: DIY. How many kids would like to make their own games, however small? Yet it had very little advertising. It's a gimmick, but I felt it was best to use it as an example.)
Even a game like this could get advertising out of heralding it as a "return to form" or something like that. I like the post-Touched games, but people who fell out afterward are out there, and they may need some incentive to think about coming back.
SurrealBrain already summed up my opinion. But yeah, I'm sure it would sell with some marketing, because it's a very good formula. In fact, it may be even safer sales-wise, as there shouldn't be the risk of people complaining about the control scheme or something like in Twisted and Snapped. And... we know the basic microgame formula works, so it won't be hard to make it a good game, which is obviously also attractive.
Would it "sell"? That's quite the question. From the suits perceptive, there's ton of thing to consider before greenlightning a new game:
-Budget. How much does making a WarioWare game cost? While their development times are quite short (Touched! was developed in five months), the dev teams are actually quite large.
-Brand perception. Did Snapped! and Game & Wario do genuine damage to WarioWare's image as a quality game series?
-Opportunity cost. Would the money and man-hours needed to make a new WarioWare instead be better spent on Hyrule Warriors 2.... FEATURING ISABELLE or Rhythm Heaven 3D: Rhythm Heaven Harder?
-Do the developers even want to do it? My interview thread shows the WW dev team has strong opinions about making purely iterative installments.
and that's not even getting into post-production snags such as bad release date or a poor critical reception.
There's so much to consider we're not privy to, and it drives me nuts. So as a gleefuly uninformed message board dweller, I'll simply say that in my anecdotal experience, the thirst for a "non-gimmicky" WarioWare is real and that a good, decently advertised release could be profitable.
I may be in the minority here, but I would like to see a WarioWare: Remixed! that mostly features games from previously released titles. One of the ways the titles could be remixed is to change the input method for the games (e.g. instead of using motion controls, use the stylus), or if they wanted to be lazy, the remix is in the mash-up of control types itself (e.g. in one microgame you use the stylus, in the next you use motion controls). OR the gimmick could be that each microgame can be completed using 3+ inputs (camera, microphone, stylus, motion) and you have to use the input shown on the game's start screen (randomly generated). With the improved memory/processor (or whatever it is) of the New 3DS you might even be able to play some of the Smooth Moves microgames.
The only problem I see with this idea (and with the WarioWare series generally speaking) is that Nintendo seems to be keen on this 'NES Remix' series... do you guys think it has invaded WarioWare's niche market?