Actually, the Scion XB (old version, as pictured) has on-rode driving dynamics that are more car-like than truck-like. While it barely exceeds the external aesthetics of an Aztec, it has quite a bit of room inside, 30+ MPG efficiency, $14k list price.

That said, I think the best solution for the GMC Yukon person is a cargo van. Or, wait until fuel prices reach $5+ and stay that way; then the US will suddenly have a large assortment of vehicles that are currently only used everywhere else in the world but here.

The Scion has 74 cubic feet of cargo volume.
The Chevy TrailBlazer has 107 cubic feet of cargo volume.
The Honda Odessy Minivan has 147 cubic feet of cargo volume.

The Scion wins out on MPG at 33mpg HWY.
The Chevy Trailblazer gets 20mpg HWY.
The Honda gets 25 mpg HWY.

The Scion wins out on price as well. $14k.
Honda minivan is $25.6k
Chevy Trailblazer is $25.8k

If you need good gas mileage AND big cargo capacity, minivans are the way to go. Just take all the seats out, and BOOM, cargo room. If you don't need as much cargo space, the Scion is the way to go.

Well, we could sell the used Pukons to countries with subsidized gas prices.