Here's one for the schadenfreude files - VMWare users running ESX 3.5.x Update 2 will be unable to power on their machines today / tomorrow / everafter until a fix is released by VMWare to correct a licensing bug that causes legit copies of the software to expire on August 12th: http://kb2.vmware.com/kb/1006716.html. Looks like it's already hit some Aussie users and other assorted folks who live in the future.
Sometimes - I guess - it's better to fail open. :)
p.s. - love the "roll the clock backwards" workaround mentioned in the VMWare forums.