Fris...
If you're going to be editing 1080p videos, I recommend the Core i7. It means the difference between being able to get it done, or not being able to get it done.
I work with the 920 processor. It's $9 more expensive from NewEgg, and consumes 130 watts versus 95 for the 860 variety. I believe this translates to a bit better performance.
For me, 6gigs of memory has been mostly fine... but I have run the machine out of memory stitching together massive 200+megapixel panoramas.

That's the one situation where I wished I had more memory.