The other day, a Mario Galaxy movie was announced. Many people are hoping for Wario to appear in that movie, but I want to see a movie about him instead.
Wario has a strong sense of uniqueness and has built his own worldview, so I think that makes more sense.
A short Wario animation would also be fun. It would be amazing if the movie were based on Wario Land and the animation on Wario Ware.
If there is to be a Wario movie. It has to be made by people who somewhat care about it as Wario doesn't work in a very generic plot like Mario. A Wario Movie could be really cool but there is just way too high of risk of a lot of animation companies messing it up by diminishing Wario to fart jokes and since Illuminations is behind the Mario Movies and as such would be in charge of this hypothetical Wario Movie... I don't think I need to elaborate any further on my concerns.
A Wario movie never really crossed my mind because he never appeared in the first one, but if he DID show up and steal the show, and went so far that they would consider giving him his own spinoff movie, I think that would be proof enough that they're doing something right! And since the Wario franchise in general has a lot more freedom with breaking rules and getting away with stuff Mario can't, I bet it would be awesome!