I believe HDCP to has compel Apple to update the ACD's sooner. When they offer a blu-ray optical drive, the displays will need to be HDCP compliant.
well for me though HDCP isnt important so I just went ahead with the 30".
I honestly only care about the led + maybe H-IPS displays, but for me though I could care less about HDCP as I dont work with bluray contents for work and have a even better hdtv at 52" bravia xbr4 with a full surround hifi system with a ps3 for a real true experience in viewing bluray movies.
One thing I DO want is an optical bluray burner for burning massive amount of data onto 1 bluray discs but other than that I'd never play a bluray movie on my mac pro, just like I never did with dvd's or hddvd's and especially since x264/h264/mkv/wmv/ogg/avi movies are available on the *ews******(not suppose to say) to watch real quick on my current mac pros with the 2560x1650 and 1920x1200 anyway. But like I said I would love to be able to burn all those formats onto 1 single bluray disc for storage other than my 1tb drives.