Despite the strange overly generous support (GigaOM articles Facebook OS, Who Owns the Apps) of intellectuals all across the blogosphere, I find most Facebook Apps to be very disappointing. Basically my complaint isn't that they look ugly or lack functionality (which they do), my complaint is that they operate too independently of the websites they try to emulate. Which means they take too long to update or require inputting all new information. When I make changes I expect them to be immediate instead of having to wait an hour.
Overall, I think it's a huge overstatement to say that Facebook or other social networks are an OS of sorts. I think DataPortability.org and Mozilla's Weave have a much better chance of becoming a real source of OS like power. Widgets/gadgets are neat and Facebook does a great job of trying to connect the data from varying websites, but like I'm trying to get across there are serious problems with this platform.
EXAMPLES:
Jaman - Moviematch
This application doesn't connect in real-time to the changes you make on Jaman, if it does it must be seriously delayed.
Finetune
This application doesn't do anything intelligent. I had to re-add all my favorite musicians and music. I did try directly going through the website to add one of my stations and so far have had little luck getting it to work.
Flixster
This application won't let me pick any of my movie lists, I have several. Instead the only list I can show is my favorite movies which ends up showing the same five or ten movies every time, depending on where you put it.
Trend Hunter (removed from my profile)
I swear the news on this thing takes forever to update. It's been talking about trash bags for a week, that's like week old news.
Amazing Wish List (removed from my profile)
This thing has a hard time gathering thumbnail images, and I'm sure it doesn't shuffle my content nearly enough (I set it to be random). BTW, I have a huge Amazon wish list.