In addition to the points listed by others, my own wishlist would include:

1. "It just works". This, the user experience, is really the most important thing. It means not just must the product work flawlessly and reliably from a technical standpoint, but it must also be easy to use from the user's perspective. In other words, a simple, intuitive, easy-to-use interface.

2. Beautiful esthetics: elegant simplicity. Apple products (computers, iPods, iPhone, etc.) are good examples of beautiful, elegant design coupled with a great user interface coupled with good, reliable performance. One thing you do NOT want is a complicated unit with hundreds of buttons and switches. Have a few essential buttons/switches, and put the other functions into the digital GUI (controlled via computer monitor or TV screen).

3. Anyone that's going to spend this kind of money on AV equipment is very unlikely to still be using dated analog equipment. So limit the analog inputs/outputs to the minimum, and focus instead on digital inputs/outputs, especially HDMI.

4. One issue I've had is with my equipment not playing/cutting off the first second of audio tracks on some CDs. After researching this I eventually discovered that it has to do with newer CD/DVD players, which stop the bitstream between tracks. Older CD/DVD players do not stop the bitstream between tracks, but emit "digital black".
Stopping the bitstream means the player and pre-pro have to "restart" the process of determining what kind of source this is (CD, SACD, DVD, audio, video, etc.) and firing up the appropriate circuits, which then causes the first split second of the track to be lost. A contributory cause is that
older pre-pros do not retain their "state" after stopped bitstreams, while newer pre-pros do. This means older pre-pros lose the information about the kind of source being inputted, which causes the missing first second of each track after stopped bitstreams, whereas newer pre-pros retain the information and therefore do not exhibit this problem.
So both source equipment and receivers need to be designed to allow the option of switching between emitting digital black, or stopping the bitstream between tracks. That way, the user will be able to listen to both older and newer CDs on any combination of equipment without losing the first second of audio tracks.

Johann
Axiom Epic 80-500
Emotiva LPA-1 and LMC-1
Oppo DV-981HD