So Vista's got this thing where it assigns a number between 0 and 5 to the performance level of the components in your system, and then your system overall. I'm extremely skeptical of this... it just seems like an idea doomed to failure from the very second someone thought of it.
1. We already tried this like a decade ago. It was called Multimedia PC, or MPC, and it ranked your system with a number based on your components. Then you could just look at a game, see that it required a Class 1, and if you saw that you only had a Class 0, you'd need to upgrade. But, nobody liked the idea, because boiling a system's overall performance to a single number is fairly absurd. Of course, maybe it failed just because it wasn't backed by a single major company like Microsoft.
2. Nobody's going to agree to terms. Of course Intel and AMD are both going to say that their Processor Whobazz is faster than their competitor's Processor Zizzle Extreme and deserves a higher ranking than Microsoft is giving them; they practically have to.
3. Unless I'm grossly mistaken and we hired a bunch of industry experts, Microsoft doesn't have near the experience that long-time benchmarkers such as Futuremark have, and even their benchmarks aren't a perfect description of performance in a single number.
My prediction is that this system will be used by a couple big companies, they'll give up on it, Microsoft will ship it again in the next version of Windows regardless, and then in the following version they'll remove it because it's dumb. But, hey, Windows division, prove me wrong.