The ultimate performance version of Cadillac's new midsize sedan, the CTS-V will hit the streets with at least 550 HP. We drove the standard 304 HP V6 version of this car a couple weeks ago and found that powerplant more than adequate. It doesn't offer the seat-crushing torque of the Hemi in my current ride, but almost any driver would be satisfied.
The Hemi has 340 HP and pushes 4,046 pounds around (in the 300C).
The CTS-V's turbocharged V8 will be pushing a little more than 3900 pounds with at least another 110 HP.
For some perspective, consider the standard 2008 Corvette has 430 HP. The Dodge Viper, with an 8.4 Liter V-10 just tops the CTS-V at 600 HP.
I probably won't get a chance to drive one of these, and probably wouldn't want to own one.
I don't even know how you'd find a way to enjoy that kind of power in a passenger car. I get into enough trouble with what I've got.