It's not long before a decent PS3 emulator for PC appears anyway. Also, I think the people claiming that gaming on PC will soon "die", are shortsighted.
I hear that HalfLife Episode 2 is only going to be released on PS3 and not PC? WTF is up with that? HL was born on PC!
It'll be 2012 b4 you see a PS3 emulator. There still isn't a useful PS2 emulator today (that plays anything other than Guilty Gear) and the system is 7years old. This has nothing to do with the Power of the console (PS2 or PS3) but the architecture differences between closed and open box systems.
Don't know where you heard the HL-2 Episode2 rumor but it's false. And just like someone advised above, you should not listen to any and everybody about such things. There are 2 primary reasons why this wouldn't happen and they are related.
1. PS3 is powered by NVIDIA G7X based RSX GPU (Valve and ATi anyone?)
2. How would you distribute Episode2 on the Console when not everybody will have broadband connectivity esp considering that it's still a single player experience.
2a. Nobody shows of their engine abilities on a Console when they have the PC as an option

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PC isn't more expensive than Console as such.
R6K gfx cards are only a situation that exists in SA where you get ripped off. That is not the case in the rest of the world. 8800GTX at BestBuy is R4,338 and GTS is R3,250.
The PC is not going to disappear as a gaming platform because for 1 development is done on the PC primarily and it is the cheapest medium to develop for in terms of development time, what makes it expensive is the accommodating of different system setups etc...
If the Console kills the PC as a gaming platform, instantly ATI/NVIDIA/MS DirectX division go out of business and that's not going to happen.
These next generation consoles can do nothing that a GF6 can't from 2004.