Although generally Skype is very reliable, I think this does make a case for open, distributed systems, at least when it comes to something that many, many people and organizations are reliant on.
People make this argument every time something quietly critical fails or doesn't work the way they want it to. As a recent example, look at the completely false FUD about ICANN "seizing domains"; there were nearly instant calls for an "open, decentralized" DNS. It's almost as if these proposed solutions wait for the slightest problem to occur, then everybody rushes to pitch a Tor utopia. I personally would greatly fe…
And as michaelchisari said, we already have distributed IM via the magic of XMPP federation.