Hey. Let's say I've been fighting with two handed weapons until now and spending perk points in that tree, and I now found a completely awesome one-handed sword and want to go sword & shield instead. Is there a way to unlearn the two-handed perks so i can put them in one-handed and blocking instead?

I would also like to know the answer to this.

Nope, there's no way to re-spec.

Not without opening the console and doing things the "developer" way. Maybe a mod will come out soon. But in case you were wondering...

http://elderscrolls.wikia.com/wiki/Console_Commands_%28Skyrim%29

Removing is player.removeperk (its not on there)

Remember, this is the unofficial, backwater way of doing it.