For my smaller enterprise I simply can't pay out to upgrade out machines to 7. We will get Win7 on our next hardware refresh cycle but not until then. As the IT guy I am very careful to monitor for malware, script kiddies and the like. I have however, resigned myself to the fact that if some uber hacker wants to get into my system they will. I have planned for that contingency. I'm not running to Redmond with piles of cash screaming for them to protect me.
Cheers