Q: Is there an up to date airprint capable printer list other than the one from Aug, 2012?

Most printers have updated the drivers/firmware.

So the list is still valid.

Anyway, you can do a search on the Internet.

OS X- Printer and scanner software available for download dated 2/21/15.

List of supported AirPrinters.

    http://support.apple.com/kb/HT4356

Last Modified: Feb 13, 2015

To widen your search there are a number of free apps that allow for printing from your ipad over wifi. These are not air print printers but you will have to check out the apps to see which printers work with the apps. I use the Canon app and it works very well. Epson I believe has one and there may be others.