Most of the provisions of the Leahy-Smith Act will take some time to be effective. Thus, for instance, the first-to-file regime will only apply to patent applications with an "effective filing date" that is 18-months from enactment.
One provision that will have an almost immediate effect is the 15% surcharge on USPTO fees as does the new $4,800 option for prioritized examination. Those provisions state that they "shall take effect on the date that is 10 days after the date of the enactment of this Act." The new micro entity status (75% reduction in fees) appears to be poised to begin upon enactment.