ORIGINAL: Ben Lanterman

You mean the Wright Bros couldn't hover??

The fuselages would look the same because people need to sit in it and the fuselage drag problems would be the same. Wings would be smaller but would have the same aspect ratio, sweep angles and other things because drag would still need to be minimized. The motors (assume propellor driven) would be smaller and less weight for the same power and still smaller for the lighter weight of airframe. Since aerodynamics are still the same you would end up with a light airplane that goes just about the same top speeds as now. The fuel flow would be a fair amount lower because of lower weight but since there is only so much energy per ounce of fuel to work with as you hit the high drags at high subsonic Mach numbers it might be close to the same.

Aerobatic machines would have the biggest benefit however there is still benefit to lighten as much possible and to use only as much motor as you need.

It is certainly an interesting queston.