A curiosity, but not all that important. I just deleted windows live messenger off everything as it was mainly a way to keep in touch with SL freinds when they were offline. Ditto on the secondary skype account which is also in phaseout mode. I haven't yet put the remaining skype account in freinds only mode but I might at this rate. Its used almost entirely for regular telephone calls at this point.
Skype was another SL relic, from just before SL got its own voice capability and everybody was doing skype conference calls. Its still useful as unlimited outbound calls are a whopping $3 a month, and what everybody else considers a bug I consider a feature - mainly that outbound caller ID just does not work on skype equipment. Great for calling people I don't want to hear back from, though GrandCentral does a fine job of doing that filtering anyway.