Not to state the obvious, but we should look to see where new (totally new) formats have come about in cameras, and where they have worked and why. Surely, Leica has done this as well
The first lesson is that photographers are a pretty cautious and conservative bunch - note our attachment to 35 mm format, lenses, etc. long after most of us have shot 35 mm film. Same with MF.
The most significant change was the intro of the point and shoot, and the small sensors - which threw the photog for a loop (what size is that lens now?), but brought reasonable quality, ease, portability, and cost to a whole new range of consumers. Lesson there: if you go downmarket but give quality, people will accept change.
At the upper end of the market (MFDB, Pro DSLR), change has been slow. The market is thinner, the lenses expensive, the investment sizable. It also is more complex to make product at this end of the market, where the pro photog wants all sorts of things that are slightly out of whack with the small size of the market: they want flexibility, quick and reasonable service, upgrades, lesser cost, etc. That sector of the market hasn't been responding quite as fast as we'de like, but there is some modest change over the past 5 years: the product is better, the cost is less, and the usability is greater. Not dramatic, but steady.
Consider the other odd solutions: 617, XPan, etc. Most of these are niche markets and if the combo is just right, people will make the switch. Like the 645 - if you meet the new format needs of most of your clientele, smaller and yet with high end quality, people will make the plunge. Miss that window, and its a cold day in the rain. Hassy almost got it right with the Arc View, but even that was a bit too much money, a bit too much, and was shortlived.
So where is the S2 in this scenario? FIrst, its a new system, which is dangerous ground already. Their concept is to provide MFDB quality, practically 35 mm size, and integrated higher levels of functionality. This is a great concept, and a good starting point. Its sound thinking, and has appeal. Imagine the Contx 645 redone for integrated digital. Or the Phase/Mamiya really done right. Nothing wrong with this idea.
But the problem is in the execution: there is no problem with Leica's detailed execution (given enough time and money) but its the cost issue. Price point is the killer here. And Leica, and most of its European colleagues, have not been willing to show a lot of flexibility in this issue.
Look at the others: Hassy has been the most innovative. They start with basics, they understand a package deal, and have done a pretty good job of changing their models and keeping much of their client base.
Sinar isn't a great model so far. They have begun to show some business awareness, but their M camera (also a flexible platform) hasn't been well situated in the market. Their new Arc-Tec is a wonderful design, but the pricing gets to be seriously...high by the time you add lenses, etc.
Leica.... well there's just not much evidence they know how to deliver a product of this complexity to a broader market. They do a good job of pricing to their constituents, and meeting their costs (we hope), but recent events (their rising prices, and our shrinking pockets) don't auger well for this situation.
I just keep looking for the magic answer here. I remember when, in the early 1990's, Rollei priced a 6003 complete with lens for $3k. Irresistable, and set up a whole pathway for some of us. Hard to imagine lots of people jumping ship for $30k.... but maybe they'll prove this to be the case. I sure hope so - its great idea, and great lenses are always good to have.