Hsu survey
Additional wood veneer choices like cherry, bird's eye maple, ash, rosewood, piano black
For most, this is probably not a make or break issue in their purchasing decision. However, having more choices would probably be appreciated by nearly everyone.
For me, it's piano black.
Bookshelf type speakers
The reputation of the current product line suggests that bookshelf type speakers would also be high quality, high performance.
DSP technology
Incorporation of any technology that can improve the listener's experience is a good thing.
edit: Just thought of one other thing (OK you only wanted 3, but I can't help myself). How about making the 5 year warranty standard for the electronics?