Toyota Prius - How would you change it?

Multiple Prius derivatives inevitable

Some day soon, Toyota will begin rolling out new hybrid cars, a bit different than the current Prius, but that will also utilize the Prius name plate, such as a larger crossover Prius, or a smaller city Prius. Shoot. Maybe a convertible Prius, or a two seat, sporty Prius. And, of course, a plug-in Prius.

Setting aside plug-in functionality, if it was your task to develop a new Prius derivative, what kind of car would you craft? For me its always been a small as possible city car, a Prius that would challenge the Smart Car in terms of size, but with more than twice the fuel economy. What about you?