Update: Unlike many other blogs that linked to this post claim, the rumor isn't about AirPrint being cancelled. It's about AirPrint through shared printers on Macs and PCs.
When Apple released the first beta of iOS 4.2 for iPhone, iPod Touch and iPad, they also officially announced AirPrint, the wireless printing system that would work with specific HP printers and shared printers on Macs and PCs:
AirPrint is Apple’s powerful new printing architecture that matches the simplicity of iOS—no set up, no configuration, no printer drivers and no software to download,” said Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing. “iPad, iPhone and iPod touch users can simply tap to print their documents or photos wirelessly to an HP ePrint printer or to a printer shared on a Mac or PC.
We have been told from a few Mac developers that a few days ago Apple removed all the references to printing via OS X 10.6.5 and PCs both from Readme files and other online documentation posted in the iOS developer center. It seems like all that's now mentioned in the release notes are the aforementioned HP networked printers, as if the shared printing option never existed. See here, here and here.
The removal of references is indeed quite strange, and Apple's developer forums have been filling up with questions about it. A developer writes that he contacted Apple's Tech Support, and they confirmed that the feature has been "cancelled":
So, here is the reply from Apple Tech Support when contacted:
Support for AirPrint on Windows and Mac has been cancelled. We will be in contact with you if another opportunity arises in the future.
An excerpt from Apple's online docs:
Applications on iPhone, iPad, and iPod touch devices can print their contents to local printers.
Other developers chimed in, and claimed Apple removed the feature due to its instability and incompatibilities. Others confirmed that the feature is still working on iOS 4.2 GM through the previous 10.6.5 beta posted on the iOS dev center, and it even works under the Simulator. No word about the 10.6.5 seeds Apple released in the past days. You can read the threads here and here.
Obviously we won't know for sure until OS X 10.6.5 and iOS 4.2 are released, but if Apple really removed support for AirPrint via shared printers -- it'll become a lot less useful for most users.