I'm sorry to tell you that it probably won't run all that well. Battlefield 2 uses shaders a lot, which will impact performance on the GMA 950 in the Macbook. It might be playable if you reduce the detail significantly, but I don't have experience with how BF2 scales. See if you can find benchmarks for Battlefield 2 running on the GMA 950; it is a fairly standard part.
The Macbook Pro has an ATI X1300 which will run it fine, however, so you may wish to consider the MBP.
I haven't tried out BF2 on the Macbook, so I can't speak from experience, just specs.