You're forgetting a very important point, though.
If I understand properly, the addition of maneuvers (or powers, or techniques, or whatever you want to call them) isn't just an "add on" to classes like the fighter. It's as integral to their repertoire as spells are to the wizard. I think one of the primary reasons for the removal of the "full round action" is that it's no longer necessary, because martial characters will be using maneuvers as often as wizards use spells.
And a great many of those maneuvers--again, if I understand properly--are weapon-based.
So yes, there will still be plenty of reasons for using a rapier, or a rapier-dagger combo, because it'll rely on a different array of maneuvers and techniques than the greataxe or greatsword will.