Well, I thunk that the core should be compatible with DTS ES amps, as this would cover pretty much all amps/receivers/processors made in the last 8 years.
I am willing to bet there are more users with ES equipped amps in use than with only DTS 5.1, especially amongst those who have adopted the Blu Ray format.
What about DTS Re-Encode? Could the 6.1 or 7.1 HD tracks be re-encoded into DTS ES? This way, players could be made to re-encode all HD tracks (DTS MA as well as TrueHD) into a 6.1 ES track. Or better yet, I wonder if it would be possible for players to re-encode into 7.1 DTS 96/24, so that legacy amp owners would get very near to uncompressed audio via SPDIF.
Would it have the ES flag do you know? I have LTOR BD, but at the moment, I only have my AVC-A1SE set to 5.1 (other 2 speakers not connected up yet). May be I need to set the amp to 7.1 for it to display 6.1 ES on the front of the amp when receiving the core from LTOR?
The DTS website does say that the core it limited to 5.1 though.