AirPrint printer sharing using Apple TV

As noted in my question the printer requires a firmware upgrade to become AirPrint compatible. What is not clear on HP's AirPrint website is how one goes about updating the firmware. Playing with the menus on the printer I finally found that attempting to access the web apps menu causes the printer to check if it has the latest firmware. The printer then determined that it did not and proceeded to download and install the firmware update. After the update the iPad lists the printer as an option for printing. My programmer brain was probably making this too hard looking for a non-consumer friendly way of doing the update. That said can't say opening up the web apps menu is the most obvious way to check for a firmware update.

I know this isn't directly what you asked for, but if you are looking for a non-techie approach to sharing printers via Airprint, you could do far worse than to use Printopia. It's not free, but it isn't expensive and it works very well indeed.