This is really basic but well hey, spinning shiney things intrigue me.

rdesktop -f -r printer:HP-Officejet-Pro-8500-a909n 192.168.22.5

Basically the above says connect to the remote desktop on 192.168.22.5 and go full screen, make the local "HP-Officejet-Pro-8500-a909n" printer available to the remote desktop session.

I tried this and over a slow Wireless Broadband link, printing from a Windows 2003 Server the print job took about a minute to come out.. and I believe it was only that slow because I forgot to fill the printer tray.