As this thread seems to have developed into a 'what would we like' one rather than 'what to expect', I'll add my tuppence.
1. Class D Amps for smaller size (would please my wife
giving higher power at lower price points (higher power = better audio quality)
2. Software updates every year (chargeable, say £100-500 depending on model, and would compensate Denon for less frequent hardware releases)
3. Ethernet over HDMI. Yes, I know this isn't for purists but they don't have to use it. I would just like it so that I can turn all the varous wifi devices off such as TV, BDP etc without having to bother running Cat5 cables.
4. Better GUI. Denon are better than they used to be but why isn't a high end device as easy to use as an iPad or a Windows 7 Media Centre machine?
5. Get rid of archaic connectors such as analogue radio (totally unnecessary if you have broadband) and composite (if you've still got something using composite, through it away and buy a new one of whatever it is BEFORE you buy a new receiver)
6. Front HDMI on all models