Well if you look at the specs of the mac book you will notice that it comes with
-1.83ghz intel core duo
-512mb ram
-Intel GMA 950 graphics 64MB
This system is clearly not designed for gaming, however im sure it would run the game to an average degree. Bear in mind you can choose to upgrade certains parts of the macbook when buying.
Looking at the macbook pro We see
- 2ghz intel core duo
-512mb ram
-ATI Mobility Radeon X1600
Much better for gaming, however the ram could be a little higher.
Also search around for the basic specs for the game BFME 2, and go for the recommended settings if you wish to play smoothyl and with great detail. Have fun choosing.