What printing features do you need? Postscript?
If you're looking to use current or future HP printers, this discussion would be best held more directly with the HP OpenVMS folks.
If you're rolling your own support, then printers with Adobe Postscript or with a good Postscript emulation and bi-directional communications should work with DCPS. The obvious wrinkle: a bad Postscript emulation can be a problem, and there are a number of those around, and some printers don't have bi-directional communications.
For "tricks", see the so-called "unrecognized" printer configuration information in the DCPS documentation, and related that occasionally gets posted here in the forums and over in comp.os.vms newsgroup.
Here's a general IP-printing topic I wrote up a while back:
http://labs.hoffmanlabs.com/node/129AFAIK, HP hasn't adopted support for specific features of MFP-style printers with OpenVMS such as scanning; Postscript or an emulation and the communications path are key here, regardless of the sort of printer.