I'm running CS6 on my MPB bought ealry 2011 and it's been great
My specs are
Processor 2.2 GHz Intel Core i7
Memory 8 GB 1333 MHz DDR3
Graphics Intel HD Graphics 3000 512 MB
Why don't you download the CS6 trail version and give it a spin.
Regarding hardware: If Premiere Pro CS5.5 is working well on your system, then so will Premiere Pro CS6.
What specific detail of the Premiere Pro CS6 requirements had you thinking otherwise?
I was reading about the supported graphics cards and the amount of vram they had. I guess that has to do with the accelerated playback, etc.