AirPrint discussion.

The issue is that AirPrint is embedded in the OS and is a general printing architecture, tailored to the OS and mobile devices and doesn't have legacy support for older operating system environments. It's also an attempt to control output, so consider if you will iCloud coming..... Then having a restricted but robust print framework, it makes sense, and cuts down on support.
HP and Apple have an agreement to release AirPrint compatible products until sometime in 2012 when the code gets licensed to other print vendors. At least that's how I understand it today!!!