I'm running on BootCamp Windows 7 MacBook Pro.

Intel Core 2 Duo @ 2.66 ghz
Nvidia GeForce 320M
8GB RAM

I get about 20-30 when adventuring the land.
About 20-30 in cities and sometimes drops to 15.
30-60 when in caves and dungeons.

I'm playing on all low as well. Is there also a way I can make Skyrim utilize all 8 gigs of ram?

It probably is utilizing all 8gigs of RAM...eventually. But Ram isn't everything, it looks like your processing speed is what is slowing down how fast your mac is utilizing the RAM and therefore how fast Skyrim can move data into RAM. I'd recommend getting a faster processor, and checking out the clock speeds for your system as well.

That's too bad. The box said a Dual Core @ 2.0 was all that was needed