Am I correct in assuming I need the hplip backend because this is an HP printer?
AFAIK, all modern HP printers need HPLIP for CUPS. The question is, which one? I have hplip-3.14.3-os2-20140427.zip and hplip-3_12_10a.wpi. The first is newer, but it installs in a completely different way than the second, older, version. If you have both of them, both will show as an option. The second one works with CUPS 1.4.8.
I have been through the CUPS 2.0.0 setup about 3 times now (using each version of HPLIP), and I cannot get CUPS to print to either my HP D110a (WiFi connected), or my HP C4180 (USB connected).
I think that I have all of the parts mentioned by Pete, plus HPLIP. installed. I did remove all traces of CUPS, HPLIP, and Ghostscript, before re-installing. That made no difference. I also tried psprint-30_905.zip, which seems to partly break CUPS 1.4.8 (could be the old Lotus SmartSuite bug, which I haven't seen for years), but it made no difference with CUPS 2.0.0.
At the moment, I need to remove it all, again, and start over. Then, I need to extract a usable log file.
I will note here, that I do not even attempt to get scanning working with these printers. The D110a (WiFi connected) has a built in web page, where you can scan, and then simply download the "picture" using the browser. This is far easier, and far more effective, than messing around with HPAIO, and TAME. I think that all recent, network connected, HP printers have that feature.