What a disappointment! First, there is no connection between iLike and the iLike-Facebook-app. To add songs to the iLike-Facebook, you must do it manually. Ick.
Next problem, the iLike sidebar is very buggy. It seemed to keep my CPU utilization pegged. It didn't matter if I was listening to a song or nor, or if "hid" the bar. It's obnoxious anyways, taking up way too much real estate for an application that is a complement to another (iTunes.) When I realized that the songs I listened to on iTunes were not showing up on Facebook, it was obviously time to uninstall iLike.
Ok, so back to Facebook. I like the idea of their platform. It's much of a real platform than any of the widget/gadget/whatever platforms out there. They give you access to Facebook services, and give you UI tools for integrating your app's UI into Facebook.
What's interesting to me is to compare it to Ning. A Facebook app does not live on Facebook. It lives somewhere else. It can communicate with Facebook and its UI is shown inside Facebook. A Ning app lives on Ning. The Ning app must be written in PHP. The Facebook app can be written in any language. An app on Ning gets to take advantage of Ning's scalability. An app on Facebook can see huge traffic, but your server/hosting provider has to able to handle that. You had better find some quality, cheap server hosting.
Obviously I have some special interests in all this. At Ludi Labs, the Roost website had some similarities to Ning. It was a build your own site (we didn't add the social networking adjective) using all of these great services. Of course Ludi failed and Roost was never available to the masses. Thus I find myself rooting for Ning now. I think F8 poses a real problem for them...