@Keysplayr
I don't think we can completely isolate ourselves from looking at the size of the GPU dies as well as the other costs of the card compared to the performance we are getting. While it's almost unquestioned the GT100 will be more powerful of a card than the Radeon 5870 we still have to know by how much as well as at what price. The reason is that most of us have a certain limit we can't/wont' go over when spending for new hardware even if we're enthusiasts. For that reason, the large die size of the GT100 as well as the need for higher costing parts (PCB, VRM's, etc) will affect the final price and therefore the bang for the buck.
This will affect the purchasing decisions of those looking to upgrade in the next 3 months if Fermi is regulated only to the upper end of the price scale with prices starting well above $400.
Not all of us can afford the top end gaming card of each generation. Most of us have to weigh our options and choose the best card depending on certain criteria such as performance for the dollar or if two cards cost roughly the same and perform roughly the same then we'd weight value by seeing which card performs better in the games we play.
You said it yourself, "competitive performers for competitive prices" which is the key word. Can nVidia produce Fermi at competitive prices? To a degree, I'd say yes. The 8800 series is an example of that. But with their ever monolithic GPU's, it's troubling to see that there is still no true GT200 derivatives in the lower end of the market. Even well after the introduction of the GT200 series we were getting multiple rehashed cards that were named like they were in the GT200 family but really were 9800 series chips (which were tweaked 8800's). While this attests to how great the 8800's were, it also points out the trouble nVidia is having scaling the GT200 down to the lower end of the market.
With this in mind, I wonder how long it will take for them to scale down the GF100 to go beyond the enthusiast markets. I have a lot of friends that I make video card recommendations to and pretty much all of them buy cards in the $150 range. I really can't recommend they buy an nVidia card at this moment if I can get a competitive option, performance wise, that also supports DX11 from AMD. In the last round of upgrades, I recommended a lot of nVidia cards. If my friends were to ask me for upgrade advice in the next 3 months, it'd almost have to be an AMD.
My next laptop, which I am likely to buy in 6 months, will almost undoubtedly have a mobile Radeon 5 series solution. nVidia likely won't have a DX11 mobile GPU for at least another year.
The monolithic nature of nVidia's chips means it's harder for them to scale them down and is affecting the purchasing decisions of lower end users as well as mobile users.