The audience cheered on Sept. 1 when Steve Jobs announced during Apple’s (AAPL) fall preview that wireless printing for the iPad would be included in iOS 4.2, the new iPhone/iPad operating system said to be coming Friday, Nov. 12.

It was one the day’s biggest applause lines, but it has turned into a huge disappointment.

First, a press release issued two weeks later announced that AirPrint — Apple’s name for the new feature — would be available only on Hewlett-Packard (HPQ) ePrint printers or printers shared with a Mac or PC.

Now, according to several reports, AirPrint support for shared printers on Macs and Windows has been canceled. Due to what AppleInsider calls “last minute stability and compatibility problems,” the feature was removed from the so-called gold master version of iOS 4.2 sent to developers last week, and all references to it scrubbed from the Readme files.

The ability to print files is one of the most basic functions of any computer. Until the iPad is able to print seamlessly on more than just a handful of HP printers, it will not be taken seriously as productivity device. [NOTE: Lacking an Apple-sanctioned solution, a couple dozen third party work-arounds have appeared on the App Store. We’ve been using something called PrintBureau, with mixed success.]

UPDATES: “AirPrint has not been pulled,” according to an e-mail attributed to Steve Jobs (not the issue, but okay).  AppleInsider has published a long Daniel Eran Dilger treatise on how AirPrint works. And 9to5Mac has posted instructions for getting AirPrint to work with OS X 10.6.5 and the iOS 4.2 gold master.

See also:

• iPad printing: 5 months, still missing

[Follow Philip Elmer-DeWitt on Twitter @philiped]