Which doesn't happen much after a certain level. Except the essentials fighter has no encounter or daily powers that I can see, so might indeed end up spamming a basic attack all fight.
This is supposed to be an improvement how? The basic feature of the challenging aura is a fantastic one though, I will grant anyone that.
The Knight will be making basic attacks all fight, yes.
However, those basic attacks will have different bonuses based on what stance he's in - whether he cleaves enemies or just does extra damage to one guy.
In addition, when another player would use an encounter powers, he will instead use power strike to do extra damage - or, at later levels, probably bonus effects like tripping his enemy or knocking him back. The nice trick here is that he is doing this while still cleaving enemies or such.
So thus far, I am relatively confident we will see the same balance of resources as far as on an At-Will and Encounter basis.
We have not yet seen what he gets in place of a Daily power. Note we haven't seen the level 1 features "Battle Guardian, Weapon Talent, or Shield Finesse" which is probably where that 'daily' resource will show up.
I can respect WotC not wanting to reveal everything about how the class works. I think it a bad call to have not shown just a bit more, if only to put these sort of questions to rest.
In any case, it seems an interesting approach. I wish it wasn't quite so far afield from standard class design and compatibility. On the other hand, it is almost exactly how I've long felt 4E should have been designed from the start, so I am eager to see how it performs in actual play.