If you want software with the HD UI just watch:
DirecTV Firmware Watcher
When 0x576 is depicted in "green" for you receiver execute the " 0-2-4-6-8 " routine as the receiver becomes active after a Reset. The forced DL procedure will always get you whatever is "green" for your box. Late nights and early morning on weekends will get you the CE but lately 0x576 is available overnight and for long periods of time.
My personal belief that 0x576 is not the a National Release as it has evolved from 573, 575, to 576 over the past few weeks. Until something is available 24/7, I don't think it is the National Release. I presume an installer has to update a box upon install and I doubt he will wait for midnight.
That's my theory and I'm sticking to it.