So we know one handed weapons can decapitate, but, what about 2-handed weapons? I didn't see any perk in the skill tree so... what do you guys think?

Of course. Of course you can.

Don't see why not....... can we pick up the decapitated head?
Yes I'm sorta macabre and weird like that.

That, I do not know.

In oblivion, modded with DR, which had decapitation, you could pick up the gibs. No idea here.

Not to be too gruesome and grisly, but...

You could pick up Matthieu Bellamont's mother's head in that one Dark Brotherhood quest in Oblivion.
Perhaps it will be possible to do the same thing in Skyrim after someone's been decapitated.

...But that's all I'm going to say about that.

Then you didn't look close enough. It says specifically in the standing attack that there is a chance of decapitation for 2-handers.

I don't see why not. In fact, I'd expect two-handers to be better at decapitation than one-handers.

Yes,there is a perk for two-handed decap.
as far as being able to pick up the decapitated head? well,if it is similar to fallout3/new vegas then I would assume that you can. I liked to pick up the heads and throw them myself for fun haha,I am morbid like that I suppose.rejoice!