I think I'm probably somewhere in the middle of the road, but more because I feel bad if someone has given me a gift and I have not reciprocated.
Am I the only one that feels this way? Right before Christmas, I had a roommate give me a nice little gift. I hadn't gotten anything for her expecting that we wouldn't exchange gifts and sure, I felt like I should have. I ended up giving her a nice little pair of earrings I had made a few weeks earlier (and had yet to have given a purpose) and a piece out of my sister's Christmas gift basket. It made me feel better to know that she wasn't wondering why I hadn't thought about her over Christmas. Maybe I'm being "pressured by social obligations" or whatever, but if it made me feel better, why not? It's the norm of social reciprocity. I'm not opposed to playing my part.
When I give gifts, I try to put a lot of time and thought into each one because both the gifts that I'm giving and the people that I'm giving them too mean a lot to me. I don't ask that they give me anything in return, but I can't say I don't appreciate appreciation of my gift in whatever form it may be - many times a huge smile and a hug is a nicer "return gift" than anything tangible. Unfortunately for me, while I fully understand this concept when I'm on the "giving" end, it's hard for me not to feel a little guilty when I'm on the receiving end.
But no, it's nobody's obligation to buy or make a gift.
On the flip side, I think that there are constraints to this. I did get a bit upset when a secret santa a few years back didn't get me a gift. Granted, the back story needs to be explained. A friend had arranged a secret santa and I ended up with a girl and that same girl had happened to have drawn my name. So essentially that leg of the secret santa was really just a 2 way swap. I didn't know her, she didn't know me. Despite this, I went out and got her a very nice, albeit fairly generic gift (a cute thermos and a bookmark if I remember correctly). She never showed up to the exchange. A friend of hers took my gift home to give to her later, but she never got in touch with me. In my opinion, this was wrong.
I didn't make a fuss to anyone that knew her, had a good time hanging out with the friends that I knew while I was there, and didn't feel terribly upset at the lack of a gift per se, but in my opinion, if you SIGN UP for a gift exchange, you understand that it is under the premise that you are EXCHANGING gifts. I was more upset at the premise.
But no, regardless of my opinion on any gift, I am always appreciative of the thought and act appreciative of the gift even if I may regift or return it later.
I have a friend whose sister and mother are known to cry if they don't get what they want (we're talking a college student and her middle aged mother). I think that's a bit disgusting.