Apple issued a press release (and updated iOS 4.2 page) ahead of the iOS 4.2 beta that just hit.  In it, they detail the new AirPrint standard and its ability to work with HP ePrint printers.  To confuse matters slightly, HP offers an iPrint iOS app (pictured below) that does iOS printing.

It appears that MacOS 10.6.5 will also allow printing through a Mac with current developer builds offering that functionality.

“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’re pleased to work with Apple to bring Apple’s AirPrint to our fall lineup of ePrint printers in time for the holiday shopping season,” said Vyomesh Joshi, HP executive vice president, Imaging and Printing Group. “Making it easy for our customers to print anytime, anywhere, is a key priority for HP. iPad, iPhone and iPod touch customers are going to love how easy it is to print using our new range of ePrint printers, creating high-quality printed pages in an instant.”

Full Release below:

Apple’s AirPrint Wireless Printing for iPad, iPhone & iPod touch Coming to Users in November

Available First on HP ePrint Printers

CUPERTINO, California—September 15, 2010—Apple® today announced that it is releasing a beta version of its AirPrint wireless printing for iPad™, iPhone® and iPod touch® to members of Apple’s iOS developer program today, and that AirPrint will be included in the free iOS 4.2 software update in November. AirPrint automatically finds printers on local networks and can print text, photos and graphics to them wirelessly over Wi-Fi without the need to install drivers or download software. HP’s existing and upcoming ePrint enabled printers will be the first to support printing direct from iOS devices.

“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’re pleased to work with Apple to bring Apple’s AirPrint to our fall lineup of ePrint printers in time for the holiday shopping season,” said Vyomesh Joshi, HP executive vice president, Imaging and Printing Group. “Making it easy for our customers to print anytime, anywhere, is a key priority for HP. iPad, iPhone and iPod touch customers are going to love how easy it is to print using our new range of ePrint printers, creating high-quality printed pages in an instant.”

AirPrint is designed to support a wide range of printers from entry level inkjet printers to office laser printers. Additionally, iOS 4.2 devices can print to printers shared through a Mac® or a PC. iOS 4.2 compatible HP printers this fall include the HP Photosmart, Officejet, Officejet Pro and LaserJet Pro series ePrint enabled printers.

*AirPrint will work with iPad, iPhone 4, iPhone 3GS and iPod touch (second generation and later).

Apple designs Macs, the best personal computers in the world, along with OS X, iLife, iWork, and professional software. Apple leads the digital music revolution with its iPods and iTunes online store. Apple is reinventing the mobile phone with its revolutionary iPhone and App Store, and has recently introduced its magical iPad which is defining the future of mobile media and computing devices.