Read the Game Informer article and IMO this game should easily become the best mainstream FPS. With Activision churning out it's awful COD sequels (As much as I love COD, let's face it, the new ones are disgraceful) and Medal of Honor being OK, I think the amount of effort that is being put into BF3 could pay off huge.
You can't compare the Cry-engine 2 with the Frostbite 2, Crysis work good even in my pc with all in High, And BF3 is gona ask Dual core, Damn even Cry-engine 3 is better that Frostbite 2 and ask less resources that crysis/cryengine 2
Most of the enterprise's that makes games should take the crytek/cryengine 3 example and make a exelent game engine that offers exelent visual and effect and all with so low resources system
In short
Crysis 2 with cryengine 3 ask same or less system resources that crysis 1 offering exelent visual in every aspect
BF3 is gona use Frostbite 2 that need dual core, that a "Good" bad optimized game engine that offer the "same" visual as Crysis 2 but with higher system requirements
Ontopic, i wonder if this game will have a long support. Also the destruction of the buldings is awesome. In IGN reverse theatre they saw that even small bricks go boom. Not just whole walls.
Edit:
Dont rely on just the specs they recommend.
GTA IV has pretty intensive recommendations too, yet there are people who play it with Pentium 4. Those recommended specs are just wrong. They give u a picture to understand a bit - how intensive the game is. But dont be like "it needs dual core".