Some good info Kirk.
As far as the actual printing pipeline (which caused so much grief when trying to print for many), I believe Snow Leopard was a fundamental "under the hood" OS change to many elements, one of which was significant changes to how the OS interacted with ColorSync.
I haven't seen any talk of this kind of thing in all the Lion beta tips coming out, so fingers crossed they left most of this alone (or if they did change it, worked with developers to make helpful changes) and printing will by unaffected.
I always upgrade one machine on day one, but do so by cloning the startup drive to a different partition on the raid so I can reboot right back to where I was. There are several features of Lion that intrigue me including full iCloud support so I'm excited to give it a shot. But I'll boot from the SL partition when actually working until I'm confident of the new OS.