Keep it simple. That's a large motto of 4e. And I agree entirely. However, it begs the question... why give one action point every other encounter with a maximum usage of 1 action point per encounter and a reset to 1 action point after an extended rest? Okay, you start with one, get in two encounters and now have 2, you use one during the 3rd encounter and are down to 1, but after the fourth, you get another and are up to 2 unless you used one there also are are then only to 1. Why not just say "you get one action point to spend during each encounter. Action points do not accumulate." Seems so much easier and I don't think it really gives away THAT much power. It's the only thing we've seen so far that doesn't stick to the "at will" "per encounter" "per day" mechanic.