While I am having the same WTF reaction as most of you.
I must admit that I am seeing some things a little differently. Sony has wanted to be a bigger player for a while and they are doing that on the foundry / sensor side of the house. On the product end while they have the low end covered (NEX to RX), the mid-range covered (NEX - Alpha), they still don't have that killer high-end product (excl. A99). As most folks stated to spend the R&D dollars for any company to develop a high-end product takes lots of time and resources (both of which Sony has). History though shows that Sony, like a lot of other established players with resources, will commandeer a product line to shorten the window on that development (Minolta).
If you take into account Hasselblad's current CEO's business relationships and understand that most investment companies are looking to either remake their acquisitions to increase profitability or to look as an attractive investment for buyers. I see Sony and Hasselblad working on high-end versions as Sony getting Hasselblad's know-how and seeing if the teams can work successfully together (typically in my industry we call this a strategic-alliance). From Hasselblad's investors side I see it as them wanting a Sony acquisition.
This checks off the boxes nicely. Hasselblad gets bought and Sony gets its high-end line (the brand and staff essentially become a division of Sony - a la Porsche, Lambo, Bugatti is to VW). Consumers are already well prepared for this by the run of Hasselblad re-badges. So, Hasselblad brings its brand cache, plus its MF know how and Sony brings its $, manufacturing capability and senor tech. As you can see Sony is in the dominant position here but, they would get what they need to tackle the Canon / Nikon brands at the very top. Didn't Sony state they wanted to by #2 in this industry within short order (if I recall correctly)?
The flip side is if it doesn't work Sony still makes money!
Just my 2 cents, YMMV!