I try to stay out of the rumor game but I think MacStories is on to something here. It seems like Apple may be killing the ability to print via shared Mac OS X printers. That is, you can still print in iOS 4.2 with compatible wireless printers, but going through Mac OS X is dead for now.
When Apple released the iOS 4.2 gold master they also pulled the iOS developer access to a beta version of Mac OS X 10.6.5, iOS developers are no longer able to get this version of Mac OS X. There also seems to be no reference to this type of printing that I can find on the online iOS documents. Apple Tech Support according to Federico Viticci of MacStories seems to confirm this.
If true this is a major setback for iOS, and something that Apple needs to get working on. I would not be surprised to learn that this will becoming in a separate update to Mac OS X. But that begs the question – why do we need 10.6.5 before we get iOS 4.2, like so many sites are reporting…