Apple has announced that OS X Lion will be $29, available only in the Mac App Store. The company is releasing a new developer preview today, with a release in “July.”

Being Mac App Store only, it seems that Apple has shut the door on upgrading to Lion from anything lower than Mac OS X 10.6.6 or later.

At $29, it is clear that Apple wants to move its current Snow Leopard users to Lion as quickly as possible. As with all App Store purchases, Lion can be installed on any of a single user’s computers. That really isn’t any different from past versions of OS X, as Apple has never inlcuded serial numbers with client versions of OS X, but it is nice that this is no longer a grey area.

Photo Credit: This is my next…