I thought it was interesting that Sam dodged the hug--my interpretation was he'd already decided he was going to trick Cas into revealing Sam was brought back without a soul and couldn't bring himself to hug the guy out of a sense of guilt.
Also Sam's always been a Castiel liker, they have a strange dynamic, some may not feel like Sam should be nice to Castiel.. but Sam likes him.
Theirs has been a fascinating relationship. Of course, Dean has always had the "stronger bond" with Cas (as well he should), but Sam's first reaction to Cas was much more positive than Dean's. Dean was all doubt and hesitation, while Sam was awestruck. I felt sorry for Sam when he held out his hand to Cas to shake, and Cas looked at him like he was a piece of dog doody that he'd just stepped in. But over time, Cas came to recognize the good in Sam and not just think of him as "That Abomination With Demon Blood In His Veins", which was nice character growth, and I feel he and Sam became friends.
There wasn't a lot of time last season for Cas to be himself and feel any remorse for knocking down Sam's wall and leaving him to, well, a living Hell playing in his mind at all times. I've been wanting to see more of both Sam and Cas trying to regain some of that easygoing relationship they once had and Dean trying to come to terms with what Cas did (I can see Sam forgiving Cas fairly easily because Sam has made some pretty huge mistakes himself while believing he really was doing good, but Cas breaking Sam violated Dean's #1 rule, which is "Don't mess with my Sammy", so I'm not sure if Dean will ever get over it. Or if he did in Purgatory). We saw a little bit of it last season, but I'm greedy and want more <g>.
Vicky
