EzekielRaiden
Follower of the Way
I think the easiest thing to do is make a structure that basically takes the 'dark blue' powers of 4e and constructs them in a point buy form where it wouldn't be hard to figure out that you could swap other 4e powers of similar levels into the structure. The game wouldn't necessarily have Come And Get It, but there'd be a Fighter class, he'd gain his 3rd encounter power at level X, and the point buy system would tend to generate powers similar to level 7 powers from 4e in overall power level.
And certain classes would make it easier to generate specific kinds of powers - the Wizard might get blast/burst for a lower cost, the Invoker multi-targeting for a lower cost, Druid close blast, and Psion getting to spam as examples of 4e controller options.
I'm with Mr. Alhazred on this one: these kinds of proposals remove what I think might be the best part of 4e.
Simply put? 4e doesn't let you COMPLETELY suck.* You always have something you're pretty good at. Not the best, not even necessarily awesome, but reliably good. Turning it into a build-it-yourself point-buy system wrecks that completely, while opening the door for "haha, I can combine THIS Controller feature with THAT Defender feature and THIS OTHER Striker feature to do 10+Str+Cha damage to all enemies within 5 squares every round!!" crap. Which means, more or less, returning to the problems of 3e: regular players have to plan things out way in advance just to keep up, while people who obsessively memorize all the options can break the system over their knees.
*Caveat: unless you're a Binder. Maybe Vampires and Seekers too, but even they are generally thought to be okay, just on the low end.