I'll continue to post information about PrintTicket here & answer questions, however I want to also point people to a few other place that may be of interest:

MSDN documentation

   http://winfx.msdn.microsoft.com/ (WinFX^® SDK September CTP 2005)

   http://windowssdk.msdn.microsoft.com/ (Vista™ Beta 1)

XPS Team Blog:

   Primarily focused on the XPS format, but includes information about how PrintTicket as it relates to XPS.

   http://blogs.msdn.com/xps/

WHDC talks:

   You'll find a talk about PrintTicket specifically, as well as talks about a number of other printer-driver related technologies.

   http://www.microsoft.com/whdc/driver/foundation/DevNotes.mspx (look under Printing Architecture and DriverNotes)