@hash4u,
Okay, once you dent it back out, there goes the stability of the car and the wheel-- the balancing will be completely out. Nope, sorry, not taking that risk 
And in my experience, alloys which are even FAIRLY decent do not crack. It would take a LOT of force to do so. I know that from experience:
Back in the days of steel wheels on one of our 'Rollas (yes shutup); I remember hitting a pothole which was fairly small, it bent inwards and the wheelcap broke off.
These days half of Karachi is dug up, my car fell into a really bad pothole a week ago; the wheel made a terrible "thud" and got stuck inside the hole, which was surprising considering its a 17" wheel. After I forced the car out in reverse and had the wheel examined, there was no damage to it at all.
Alloys have a definite advantage over steelies, those are out like the dinosaur.