Skype crashes due to network "software issue"
Skype downloads have also been temporarily disabled, so today might not be the best day to upgrade your Skype client or sign up for a new account. Apparently if you're the sort of person that leaves Skype running in the background all day, you can go ahead and leave your client open and you'll be logged in as soon as a fix is issued.
The incident has prompted some interesting speculation in the blogosphere. One possible explanation is that Microsoft pushed out some Windows XP and Vista updates yesterday that could have broken Skype compatibility for many users. Meanwhile Om Malik wonders if the outage exposes a limitation of peer to peer technology as Skype's authentication server could be getting hammered today. It seems like anyone who was logged into Skype when the outage began will remain logged in, while most users trying to login today are having difficulty.