According to the article linked to below, HK's new 7550HD receiver has Dolby Volume and also uses "the latest-generation Texas Instruments Aureus DA710 audio digital-signal processor in a dual-DSP implementation". Not sure these are the same dual TI chips that the 997 will have, but it seems like a fair guess. If so, it seems the TI chips are capable of implementing Dolby Volume. Of course, there could be other issues in implementing it in the 997 (e.g., how much processing power the Trinnov Optimizer eats up).

I also noticed that the HK while using TI audio DSP's (like the 997) rather than the Cirrus CS497xx (like the Emotiva UMC-1) will use the same video processer (Genesis Torino) as the UMC-1 rather than the Silicon Optix Reon that the 997 will employ. I know, I know ... one's audio & the other is video so they have nothing to do with one another, but interesting to see the different manufacturer's parts choices. It appears both the 997 and UMC-1 are getting top shelf components. Note that the HK receiver is listing at $2,799.

http://www.audioholics.com/reviews/receivers/harman-kardon-avr-7550hd