freitasm: Shame really that Messenger is gone so the "Online Messaging" is really just Facebook.
I said before, the whole "People" in Windows Phone 8 should be plugin based so new platforms could be added without the need of a OS update.
For example, right now they should have Skype users in that list, as well as Facebook and Messenger (which is gone). Instead we have a half baked Skype experience (I don't get notifications of incoming IM or incoming calls) and a half baked Facebook experience.
Online messaging does include Messenger, not just Facebook
There is a Skype update coming soon, I'm running the beta and toast notifications for incoming IM and Skype calls are working fine