I dunno, it is awful early to announce or rather "release" Assist Trophy characters...
I don't think Namco knows what to do with it. Honestly, if anything, Namco could either sell the franchise back to Nintendo (which would beef up the WiiU's Virtual Console library) or they could (more reasonably) just ask Monolith Soft to make the next one (obviously exclusively on either the 3DS, WiiU, or any future Nintendo consoles), and have the original creators of said franchise make said game.
Really though, Namco has no current plans for the franchise, so at least doing something would be an upgrade. It is unmistakably an asset that hasn't yet been utilized by Namco Bandai since Monolith Soft was sold off to Nintendo, which is a crying shame to said franchise (and said fans), and simply just lost money.