Things I'd love to see in future Mustangs:
(a) hybrid technology including that clever way some of the current hybrids harness breaking power to recharge battery. I mean hey with fuel prices this high, wouldn't it be great to save a few MPG?
(b) all-wheel-drive
(c) lighter/?stronger? materials used to decrease overall weight of the Mustang to increase performance and MPG and offset the extra weight and HP loss from all-wheel-drive.
Yeah I want it all in one car and I can't afford a convertible Audi Quattro V8 yet!