Hey, I actually did that! After the April MCAT, I just knew my verbal was going to be a bit weak and completely out of sync with the rest of my application -- so, before I submitted my primary apps, I added my GRE scores to the mix (my verbal GRE was in the 96th percentile and the rest of the sections cracked the 90s as well). And, who'd a thunk it?! I got an 8 VR in April.
I don't know if the admissions committee is going to look at my GRE scores -- or even care since I'm not pursuing an MD/PhD -- but I just thought it could only help. But since the GRE and MCAT are two very different tests (obviously), my GRE scores might not help one bit. Still, if you've got another set of stellar standardized scores under your belt, you might as well take advantage of them!
Just my two cents. Good luck!
PS - Retook the MCAT in August, and my Verbal score this time around was solid -- not stellar, mind you -- but solid.