If I wear stormcloak officer gear, will imperials attack me? Btw I am allied with the imperials.

Anyone?

I don't think so.

Armor does not convey a faction identity in this game.

Sadly it doesn't,but I think it should.

New Vegas utilized this feature pretty well.

I say they make disguises one of the sneak skill perks.

Guards will comment on it though - I was wearing Stormcloak armour around Riverwood for the first couple of in-game days as I dutifully earned some cash chopping wood, and eventually a guard that I walked past commented something along the lines of "I'm getting sick of seeing you in that armour" - I thought that was pretty cool

Yeah, it was in New Vegas. Looks like they took it out for Skyrim. No biggy.

I was wearing studded armor, and a guard told me I was wearing the armor of a brigand, to watch my step. Weird. I had taken the armor off a brigand. But that doesn't mean I am one. Still, there seems to be some sort of recognition sometimes. Also, if I wear my destruction robes, there's a guard or two who will say "so you can cast a spell or two, am I supposed to be scared?"

But I haven't had experience with stormcloak armor, I just sold it.

Others will comment on it, but wearing a groups armor doesn't restrict you from any areas in the game, at least from what I've seen so far.