@ Leonedes: What resolution are you using?
A gtx 460m Is not comparable to 550ti, altough it has same number of shader. Now if we eliminate the mem speeds, and focus on core clock, the gtx 550 ti is @ 900/1800 where as the 460m is @ 675/1350. Am not insulting your laptop. It is a gaming one make no mistake.
Also here is a review of an msi laptop with i7 2630, a gtx 560m, and an ssd (note that BF3 stores textures on your hardirve, so an ssd does indeed make things run a bit better).
Here is what they got:
Resolution : 720 low, min: 44 avg: 72
720 high min: 34 avg: 49
Link:
http://vr-zone.com/articles/msi-gt780r-gaming-notebook-review--taking-the-battlefield-on-the-road/13794-3.html
Anyway, a gtx 560m is the same as your but oced 100mhz more. So i think its normal fps that your getting.