Apple today announced that its installed base for its Mac lineup is now 66 million. That number has tripled from just five years ago. So far, Apple has shipped 22 million copies of OS X Lion since its release 9 months ago, making it the company’s best-selling operating system so far. Over 40% of Mac users now use the latest version of OS X. As Apple noted, it took Windows 7 27 months to get to this point.

Apple’s Craig Federighi was clearly proud of how quickly the company’s users adopted Lion. He also stressed that this was Apple’s first operating system update to be distributed via the Mac App Store.

Apple also noted hat it now has 125 million iCloud users. Interestingly, this is the same number Apple announced in April.

You can read more about all of Apple’s updates today in our live blog here.