I personally dont think there should be a way to reset them. And for me choosing a new style of play will be a reason to make a new character adding greatly to the replayability of the game.
But hypothetically lets say that they must have a way to change your perks somehow, talking about wanting to try new perks. Since you have a limit of 50 and you gain one each time you level, lets say you play the game through to level 50, enter in all your perks then want to try something new.
I could see two different ways to do it
1) One would be that you would be able to just start working towards a different perk after level 50 but say it takes significantly longer to gain a level after 50 like 4x as long or more, and upon gaining a level after 50 (or even 60 or some higher number) you could slowly take one perk off and replace it with another lower perk and slowly learn you way in that other discipline(this would of course be a much much slower process than orignally just leveling your character)
2) And the second way i could see it would be to allow the possibility of switching a few of your perks very early on in the game at a lower level such as 5 or 7 or something but after that its impossible to switch them.
But for me i think since you can see the entire tree from the beginning and you play the game how you play it without anyone telling you what to do, everything comes naturally and your perks come based on your gameplay you just let the perks drop into place based on that. So if you look down the tree and see something awesome you want to shoot for you work your way to getting it by using that style so you can obtain it, and if you go up many different paths you end up being a jack of all trades, fairly good at all but not amazing at one in particular.
It also depends on how deep the trees are, if they arent very deep we may be able to become well experienced in quite a few skills....and thinking on that you most likely would be able to go into all the trees you want but youd only be able to get the lower ranks of each perk as opposed to focusing in on one tree and getting max ranks. Thinking about it thats probably a good way it could happen.
any thoughts on those two ideas? or maybe on the perk trees being shallower than expected and just having many ranks to each perk.