Your symptoms sound a lot like my 1525n (non-wireless) regarding AirPrint prior to updating its firmware.
Out of the box (brand new last week) AirPrint was not supported - computers could print to it, but no iPads/iPhones could see it. There was an available firmware update for it on HP's website, though. Applied it and AirPrint sprang to life. Since then there has been yet another update posted, released on 2nd Dec.
What is the date-code for the firmware on your printer? (The "HP Utility" app displays this on the Mac, I'm sure there's something equivalent on Windows). The latest update installs version 2010-11-25.
-- Ah, I see somebody else already asked that! Never mind.
Message was edited by: Mudge