Yep, like fadedc says, as far as the opportunity fire. You have to burn your attack phase in order to "lay in wait", but that's functionally no different from reserving points at the end of your turn. It really seems like the same gameplay mechanics are available to you, but instead of having 70 points to work with, you get 2 phases.
Now, the only thing I can think of that might not work under the new system is getting multiple shots while on guard duty. Say you've got a guy in a nice hole, waiting for critters to wander by. At the end of turn one, a big ugly wanders by. You guard pops it, but doesn't quite kill it. For turn 2, you take a snap shot and finish off the baddie. You save your remaining points in turn 2, and take another opportunity shot when the next critter wanders into view. Under the 2 phase system, as it's been sketched out so far (admittedly not a detailed explanation), that would be 2 attacks in a single turn which appears to be a no-no.