Apple has made a beta of iOS 4.2 for iPad, iPhone, and iPod touch available to developers for download.
While I was downloading iOS 4.2 for iPad, I noticed this advisement:
iOS SDK 4.2 beta requires Mac OS X v10.6.5 pre-release to test printing from your app.
So it looks like you’ll need a Mac connected to a printer in order to print wirelessly from an iDevice, not quite the network printer discovery I was hoping for. This also raises the question of whether or not Apple will be releasing a Windows client for sharing printers as well? Technically the framework is already there, since Bonjour has been available for Windows users for awhile now.
I have yet to install 10.6.5 to try this out, but my spare MacBook Pro looks like a prime candidate for the pre-release software treatment.