Skype IM API has been released so that third party developers can tie in to the text only chat system of skype. No tie in with voice. For me, the only thing missing from IM right now is integration of all the various IM networks. Other than that, I already have all the features I need from an IM network.
Right now, I use AIM (work), MSN (friends), Yahoo (family), Jabber (thanks to google), Skype (Gaming friends) and IRC (Linuxhelp channels). I used to use ICQ, but most people migrated to MSN from their so, I no longer use it at all. And I have to use them, because its almost impossible to get people on one network to move to another. Can we standardize on ONE IM protocol, please!!!!