I'm going to stay optimistic and say that yes, there will be a Mario Party 11.
If Nintendo has learned anything with this game, it's probably that the diehard fans SERIOUSLY want the old form of play back. It might be more complicated than 9/10, sure, but honestly, what was wrong with the original gameplay format? It was great in 6, good in 7, and great again in 8, so the changes made for 9 still feel out of nowhere...
The car works fine in, say, Bowser Party, but as a main format, it just does not deliver. It'd be fine as an >alternate game mode.<
Island Tour isn't really an excuse either. It didn't have the car format, but it was way too simplified and was too "go in a straight line"-y for a Mario Par- actually, for a Mushking game in general.