Safari 3? Not on a corporate PC.
Just tried installing Safari 3 Beta on a (large corporate) client's PC, where although I don't have full admin rights, I have been able to install other apps in the past.
And herein lies the ultimate safe haven for IE - locked down corporate PCs.
It's a damn shame, quite frankly, as installing Safari 3 on a test PC, shows that it installs Bonjour by default. While I'm sure that's ostensibly for Apple TV and future device discovery, it would really benefit Corporate PC users with all these pesky networked printers.