I've got a question, since I can't really be bothered to read all the way through the books I don't own and will likely never use -- why are there only "1st-level" at-will powers? Why can't you swap out your measly 1st-level at-wills for cooler stuff at higher levels like you can with (seemingly) everything else?
Do other powers, well, encounter powers or daily powers, for that matter, ever reference the at-wills? Like, "jolly good, you hit with your Fighter's Cleave, here's a special follow-up power that acts as a combo!" or is that kind of thing too cool for 4e? I mean, having a class's powers reference one another would be a key reason for keeping around those same at-will powers throughout your entire career -- kind of like an "opening strike" followed by all kinds of interesting and varied "follow-ups." You know, like openers and combos and finishers in video games.
Ideally, the reason you would want to choose to stay with low-level at-wills is because they segue into cooler high-powered combos as you progress in levels. Alternatively, you could trade in your tired at-wills for more powerful or simply more interesting stuff that wasn't available at lower levels.
Alternatively ... why are some of those low-level encounter powers still "encounter powers" when you reach epic levels? Why don't they become ... at-wills after you've performed them a hundred times over the course of your career? Is WotC saying that your special sideways cleave that makes your opponent slide halfway across the room is something you can only ever WISH you could do more often?
I noticed that there are some Utility powers that are At-Will, Encounter, or Daily. How many At-Will Utility powers are there? Are any of them particularly useful? It seems like that may be the only way to gain additional interesting at-will powers. Aside from multi-classing, of course.