Keep cost down, complication within reason, design to the lifestyle of "the straights", make it cool, and have it sound something like "real stereo" (IMO it must do "the imaging/soundstaging thing").
When $1500 gets you an entry-level integrated amp (or $2000 for separates) and passive pre-amps fetch hundreds/thousands it's time to admit that the price to step into high-end audio is too high. (And those are prices from AC vendors which most here accept as quite reasonable.)
Now folks are paying hundreds just for HT setup. One look at the back of a 7.1 receiver tells it all. We also need to avoid tweaks and expensive accessories ($4000 isolation feet, $2000 wires, exotic/massive racks, dominating room treatments). Offering the simple alternative to this should be on the agenda.
Forget old technology like vinyl and tubes, think downloads and MP3. The goal is 90% of the gain for 10% of the sweat. Come to the market and where they live, don't make them "climb the mountain".
Introduce them to the magic of stereo (which originally meant "solid" as in imaging, but that unfortunately gets lost all too easily). I'd vote for small single driver speakers, like Omega Super 3 or TBI Majestic Diamond (be sure to read both 6moons reviews) that can perform as "active" speakers, focus on the heart of music (80 - 8,000 Hz), and easily fit into most domestic settings (or be moved in and out of place).
Shanling just introduced something along these lines:
http://blog.stereophile.com/ces2007/011007shanling/For $1000 USD you get CD/AM/FM, I-Pod cradle, remote, eye candy Shanling looks with exposed tubes, 3 wpc (could use more juice, especially so you could move it into the main/larger room), and it's compact. Just add a pair of small/efficient speakers (sub could come later).
Vendors will have to decide if whatever they come up with will compete with or embrace HT. Even Bose advertizes a 2.1 HT system, so John Q Public might be ready for an audiophile system that embraces video.
Vendors should also consider offering:
1.) PC connectivity for access to ripped music and internet streaming;
2.) XM downloads.