BOAC,
I think the problem is potentially serious for those many businesses who have switched to VOIP for communications.
Businesses with half a brain don't use Skype for their VoIP.
Do we know if it is a DOS, server crash, virus or what?
Skype - The Big Blog - Skype downtime today
Apparently something to do with a bug in the latest version, or so the "official" line goes.
It's a bit difficult to DoS a P2P network (not impossible, just tricky)..... although obviously one should not rule it out, my uninformed guess would be that that's unlikely to be the cause (apart from the present "official" explanation of a self-inflicted DoS )