For what its worth I just read at HTF that DPLII was orginially designed with capiblity to handle 7 discreet channels but when released pulled back to processing only 5.1 material. The poster said he assumed that gave the wiggle room for a future uppath someday, (when there is more 6 channel discreet DVD material on market and (someday 7 channel) to 'excite' us all to run purchase DPL3.
Just passing 3rd hand.