This trick has worked wonderuflly for me to speedup network printing, including XP with Service Pack 2, but how universal a speedup trick it proves is beyond my capabilities of testing.
1. Start the Printers and Faxes Wizard. Then click File, Server Properties, Ports
2. Click Add a port, select "Local port", then click New Port
3. Enter the full \\Share_Server\Printer_sharename of the shared Network Printer; e.g. \\Server1\HPLaserjet500
4. Click Next to finish adding the port.
5. Now use the "Add Printer" wizard to add a new Local printer, not a Network printer. The port is going to be the new local port you just added.
Test. On a LAN with new Epson Stylus printers connected with USB to the print server, print times were cut in half or better with this trick.
Best,
Bill Castner