I have a 2 yr old computer from Nov. 2010. I bought it as a performance desktop but not as a video editing machine ( I got into DSLR videography in summer 11').
Here are my current specs:
Windows 7 64bit
C: Drive (7200rpm) for Operating system/Programs and export/output destination. PP & AE CS5.5
D: Drive for Media Source Footage 1.5 TB Caviar Black @7200rpm 6.0GB/s
12GB Ram
i7-2600 Processor at 3.4 GHz
ATI Radeon HD 5570 Graphics Card. 
I'm saving up for CS6 production premium so I'd like to upgrade some of my machine components to confidently handle it.
I'd like to go for 24GB of Ram...that's enough for me right?? is 32 necessary for me? BTW, I'm only editing DSLR video files. Not camera files like RED etc.
Secondly, I need a solid PP/AE GPU accelerated (CUDA) videocard for editing videos with effects applied, in buttery smooth playback that doesn't bog down my hardware.
I don't know where to begin with video cards, I just don't know much about them or what to look for when buying a solid Graphics/video card? Is the Nvidia GTX 660ti good for me in this circumstance?
Summary:
Ram?
Graphics video card suggestions...?
All for CS6 PP/AE