Apple today released a PDF documenting (PDF link) how large business and educational customers with many Macs will upgrade to Lion via the Mac App Store. It appears that even for those customers, Apple will not be offering Lion via physical media. Like the consumer release, OS X Lion will be available via online delivery only.
Apple will offer business customers volume license contracts for $29.99 per license, with a minimum of 20 licenses. Education customers can purchase the Apple Software Collection (Mac OS, iLife and iWork) starting at $39 per license, with a minimum of 25 licenses.
For customers wanting OS X Lion Server, it will be available as an add-on for $49.99, in addition to the $29.99 upgrade for standard Lion. Snow Leopard Server is not required to purchase Lion Server, but existing Snow Leopard Server installations can only be upgraded to Lion Server. Both Lion and Lion Server need to be purchased for Snow Leopard Server-equipped machines.
To actually download Lion, volume license customers will receive one redemption code for each contract. The redemption code can be used to download Lion from the Mac App Store. When the redemption code is entered, the Lion installer will download to the Applications folder, but will not install immediately. This Lion installer is used to install Lion on other systems. Download once, install many times.
IT departments will be able to use the same mass installation techniques they use today. To install Lion on multiple systems, they'll copy the Install Mac OS X Lion application from the Mac App Store to each target system. Once copied, the installer will be launched and Lion will install in place. There is no need to boot from an external disk. Administrators will also be able to use System Image Utility in OS X Lion Server to create NetInstall or NetRestore Images.
Apple previously announced that it will be releasing OS X Lion in July.