Very interesting development and thanks for bringing it to our attention. I'd be somewhat less uncomfortable about the future health of the MF niche than you indicate here. So gazing into the economists' proverbial crystal ball (OK, let's set aside all that Wall St. stuff for a few moments including the economist jokes):
Firstly, one must assume that a firm like Hasselblad wouldn't be trying to price themselves out of existence. There must be a strategy behind this move, and I think that faced with these new ultra-high resolution DSLRs, it is basically to carve out a new market niche - call it "MF-lite" if you will, which would sit between "MF-regular" and Hi-res DSLR. They'd be trading on the photographers' quest for a combination of both many megapixels and larger photosites at a more accessible price point.
Even if the market were initially small, whatever their fixed costs - and much of the price probably is fixed cost, if they were to double their sales they halve the fixed costs and that can have a big impact on price while preserving revenue. It all depends on the time-old relationship between costs on the one hand, and the relationship between price changes and volume changes, which in economics jargon we call "elasticity of demand" (zingg!..........).
No question it's a gamble, but in business as you know, nothing ventured, nothing gained, and they've probably done their market research.
If my hunch were right and they are creating a new niche at a lower price point, this could pressure, but not necessarily wreck, the few remaining players. They will probably have to be specialised in yet higher end product which will still appeal to those who want or need the highest-end gear money can buy (or in other words, a price-inelastic high-end segment). Sure, Hasselblad's move could put some pressure on their overall price structures regardless of product differentiation, but perhaps we don't really know what the current margins in this industry are, and therefore how much value dilution they can afford to absorb before it really starts to bite.
Hard to say how it will shake it out in reality, but perhaps the MF industry can survive some price competition while giving consumers better value and more variety. It will always be a small, tight market at stratospheric prices, so perhaps this will all start to loosen-up - as it should with technical change, which generally expands markets and reduces costs.