First let's talk about a couple ideas that the Internet Illiterati are thinking.
This could be a great MF rig for pros
This has several variations, including people pretending to be professionals stating that they intend to buy it. This is stupid on the face of it, it's a wildly incomplete system. Yes, yes, you can adapt these specific lenses, and if you're very careful about which ones and you update the firmware you can get full capability, blah blah blah. No.
Pros will use this as a second camera
Uh huh. Because what pros need as a backup system is something that uses different lenses, different batteries, has a completely different UI, and handles differently. No.
It's so light and tiny!
Well, it's small. And it's light compared with medium format kit, but good lord it's not light. With lens it's over two pounds.
Something I have not seen mentioned is that the ineffable "look" of medium format, which if it's anything is the way focus drops off wide open, is largely or entirely negated by the relatively slow lenses. I'm not sure why I haven't seen any comparisons to the Nikon Df.
This thing is aimed at the moderately well-heeled enthusiast, not the professional. Some professionals will buy it, sure, but it's not a professional system. It's prosumer, just like they say, and that's the industry standard term for well-heeled enthusiast. But this is a great thing. The well-heeled enthusiast has, literally, always been the actual market for expensive cameras. They have funded the whole photography enterprise, start to present! Hooray for the well-heeled enthusiast! You and I are probably well-heeled enthusiasts! Although I admit to being a cheapskate.
H is getting back to its roots here. When I was young, the Hasselblad was the camera we aspired to. It was actually within the grasp, financially, of anyone with a good paying job. You just had to save up and make some sacrifices, or buy used, or both. It was a dream camera, but an achievable one. As Kirk Tuck pointed out, that all went away with digital medium format. You had to be actually quite wealthy to afford these things, and the benefits they offered were (and remain, let us be honest) extremely minimal increments over the best of the 35mm-sized cameras.
This X1D thing isn't the luxury product I was predicting, but it is very much in line with Hasselblad's history.
It also provides a useful benchmark for Hasselblad's design capacity. This thing is, by all accounts, pretty much just the 50mp back wrapped in a box. Now, the design of a box is not to be dismissed, boxes are surprisingly complicated. There's also a slick new UI. But this is not a whole new system, as far as we can tell.
But, if Hasselblad had the engineering capacity to stamp out new camera systems willy-nilly they're not showing us that.