In my opinion, if higher end manufacturers are staying away from it, it is because of the technical complexities of investing in new technology; although, with names like Classe, Halcro, and Mark Levinson developing for HDMI nowadays, it's pretty hard to make that statement.
HDMI isn't necessary if you could get past:
1. Using the DAC's in the Oppo player
2. Using speaker distance correction and crossovers in the Oppo or external analog crossovers (like Outlaw ICBM-1)
3. Losing THX post-processing capacities and room correction
There are no other major differences. I came to the conclusion that, by avoiding HDMI, the pre/pro arena becomes much larger in selection. Also, analog components will never become obsolete so long as DAC's are continued to be made.
But if you're interested in HDMI, consider the Cary 11A and the NAD M15HD that will be coming out shortly.