Could be a lot of things, and it's not really 22 franchises, I mean, we aren't getting a playable DS or wrist strap or anything, and the Professor K thing is totally invalid because the Touch Generations logo is NOT the DS logo.
Edit: @ Above, my theory is that all characters AND stages will get logos. Characters will get logos whether they have a stage or not, not all stages will have to have a character to go with them, but no matter what, all stages and characters will have a franchise logo.
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But really, is there a point in theories about new icons (beyond 22)? We know there are two icons left that haven't been shown, and besides those two we know they can easily add more. Seems sort of pointless to me.
Also, none of them would be Megaman. The podcast that hurt his chances was recorded sometime in November/December and we already knew about those icons at that time, and Sakurai had obviously not approached them about Megaman yet. So he is pretty much out of the question for one of the two existing icons unless we were lied to.