Graphics:AMD Radeon HD 6750M graphics processor with 512MB of GDDR5 memory
Ram:4GB
Processor:2.5GHz quad-core Intel Core i5 with 6MB on-chip shared L3 cache
My iMac is the late 2009 i5.

Low settings, low resolution maybe.

Any kind of meaningful setting, no.

No, unless you're a masochist and enjoy watching your games stutter uncontrollably, even on the lowest possible settings. Your video card sucks, and you have a iMac so you're not going to be able to replace it either. Excellent choice buying an iMac! lol
Sorry for insulting you but I just built a computer for someone that can run BF3 on medium settings for $600. How much did you pay for your craptastic iMac? $1200? $1500?

not that well.

I run a dual core 3.6GHz Windows PC with 4 GB of ram and a geforce 260gtx (896 MB) and both the cpu and video card are pumping hard to play it at over 15 fps on low settings. Granted my res is 1080p

EDIT: Also you would have to bootcamp Windows 7 as BF3 is not ported to Mac

I lol'd! A Radeon HD 6750M(obile) GPU trying to run BF3...

Nope. Throw that piece of trash in the trash can and build a PC.

You'll have to buy a copy of Windows 7 and install it on your Mac to run BF3. That's why PC's are for gaming, and Macs are for idiots.

Your funny no Mac in the world will ever be good enough to run games that a PC that's $500 not $2000....