The next spoiler for Avacyn Restored is an odd one with an even odder mechanic:
This seems very good to me, I just don't know how good. He's basically an outlet to give any one of your creatures double strike at any given time. Sure, there's the potential fragileness involving in pairing two creatures together to get the effect, but the cost is cheap and the ability is powerful.
What's more interesting to me is the fact that this seems more powerful as a 1-of in an already established deck. Am I crazy? For as strong as it may seem, it does no good to have 2 or more of them in play (for the most part). If one paladin is already in play and you cast a second one, their abilities are a wash. They can pair with each other, but then you're just being inefficient. When thinking up "deck ideas" I think it would be a mistake to center a new deck entirely around the paladin's ability. I think some people might want to just jam four copies of them into a tribal human or knight deck, pack it full of swords and go from there. And I think that would be a mistake.
I think you just stick a single copy into an already established deck and call it a day.