@Vamsi No, PC RAM and console RAM are not different. On PC, we use Windows as a software intermediary to run games which, even though has powerful APIs such as DirectX and .NET, does not have low level access to the hardware such as RAM, CPU and GPU like consoles do.
There is a wide variety of hardware for the PC, so in order to make their games run across different combinations of hardware, developers need those APIs. If those APIs weren't in place, we would go back to the 90s when PC gaming was a mess. The downside to these APIs is that they only work as a layer rather than providing compete access to the hardware which in turn, leads to inefficient use of hardware and eventually leads to higher system requirements.
On consoles, however, due to consistent hardware across all consoles, the developers get low-level access to all hardware including the GPU, CPU and RAM. This is the reason why games such as Uncharted 2, Killzone 3, Alan Wake and God of War 3 look and work amazingly well even on ancient 2005-2006 hardware. (ATI X1800 equivalent on the Xbox 360 and NVIDIA 7800GTX equivalent on the PS3). Let's admit it, it's PS3 and Xbox 360 vs a gazillion different hardware combinations on millions of PCs all over the world. It's less effort and higher profits vs way too much effort and negligible profits for game developers.
You can't go on bashing Crytek around for not making Crysis 2 a PC exclusive. They're a game company but still a company and they need to earn profits. And seeing the current state of piracy on PC, I completely support them on consolizing Crysis 2.