Just a quick update on this one - a Freescale rep suggested looking at the bare metal Freescale USB Stack for an example of printer support. The USB Stack supports USB printers and does have an example. I loaded the printer example into a tower system and (with a few code additions) it is able to print to a Godex DT2 printer.
I am now in the process of porting the printer example over to my MQX project. Has anyone attempted this already?
I will update this thread again when I get further along.
For what it's worth - my MQX project is already working with USB keyboards and USB flash drives.