Do you think this will be likely to happen? Like being able to swap button 1 or button 2 of any weapon with a different type of attack of the same weapon (think of it as specific weapon skill-set swapping). I think this seems to be a very foreseeable mechanic to be added in later content patches. It would deepen the game immensely combat-wise (as I'm sure they would add/have new weapon variants along with new content), and go along swimmingly with the hot-swapping of weapons mid-battle as well as the hot-swapping of class skills (6-0 buttons)--basically there would be a second set of weapon skills to modify or swap with the original weapon skills.
In my mind, this is going to happen, I am just hopeful it's sooner rather than later.
I guess as a sub question, would you rather see completely new types of attacks or be able to modify the existing weapon skills (a la gems and sigils) into something different (add another swing/cast/shot on hit, cause aoe confusion explosion, grant random boon/condition for x seconds, instant refill of energy bar, etc)?