Denon is a very unusual company in this regard and it is one of the standout reasons why they are in very high favor with the audio/video world. I would not bet on almost any other manufacturer offerring any sort of upgrade to their gear as they most likely designed and built the gear from the ground up for what is included on it.
If it's HDMI 1.1 then that is likely all you will ever get from it until you upgrade. Unfortunately, HDMI 1.3 isn't just a single chip, but adds several functions for audio and video that typically require an entire backbone to be in place for full support.
Not likely unfortunately.
