Several years ago there was bogus information going around the web that the Hummer was the more environmental friendly vehicle when you considered cradle-to-grave total energy costs (see my previous post here)
Well now comes round two of the Prius vs. Hummer and I think the Prius is delivering the knockout punch. GM is considering ending Hummer production and closing the Hummer plant (see here). In the mean time, Toyota can't build the Prius fast enough to meet demand. Dealers can't keep them on their lots and Toyota will be starting Prius production in the US (see here)
With gas averaging over $4 per gallon, the Hummer just couldn't keep pace with the Prius. In the end, the gasoline price is what cleared the air on the Prius vs. Hummer energy obfuscation. The Prius won hand down. The debate is over.