Not sure if this post is closed, but hooking up a Vidock to your macbook using the sonnet echo thunderbolt-to-expresscard adapter works. Im using an Nvidia 560. But are you sure you dont mean the 2011 macbook pro model? Because the 2010 model does not have a thunderbolt port.
Also to everyone saying an e-gpu would barely affect the performance, I beg to differ. On my 2011 13inch i5 2.3ghz, Im playing battlefield 3 at 30fps with high settings and 1080p, crysis 2 on max settings at 50fps, compared to unplayable at low settings with my standalone laptop. An e-gpu turns a laptop into a decent gaming rig.