Purely from a self interested point of view, I'm very interested in the Hy6, I think it has potential. I think Hasselblad have shot themselves in the foot with their closed system, not to mention bullshit 'full frame' advertising.
The rental issue is not of interest to me. I have never rented and prefer to buy. Maybe I'm lucky but all the equipment I have bought has been very reliable (he says touching wood), and as a professional, I always have backup so a non issue for me. When I did need repair or support Rollei, in the past, was no slower or worse the blad even though they had a much, much smaller user base. So also non issue for me.
As a long time V series blad user in film days, then a long time Rollei user, then back to blad (when Rollei, at the time didn't accept P1 backs), I have never ruled out the possibility of moving to H series... until know.
I have looked at them in the past but, for my way of shooting never jumped. I prefer to rotate the back rather than the camera, German glass to Japanese, waist level finders. Imacon backs never floated my boat and, compared to C1, Flex software and workflow sucks. Although of course that wasn't a problem as you could have chosen another back.... until know. I'm P1 at the moment but wouldn't rule out changing to Leaf or SInar in the future, as long as the camera platform is supported. The implementation of this with the Hy6 remains to be seen but, hopefully, will give me the choice... very important to me.
The old V series has proven to be a reliable, simple platform and a joy to use, although it would be nice sometimes to have the creature comforts of AF, metering and getting rid of some external wiring. Enter the Hy6. It has those added features, retains the features I enjoy, waist level finder, Zeiss and Schneider glass and retains the square format. I like square and if a rumour, that certain companies are talking with other companies about making a 48mm square sensor turns out to be true, I for one, will be very happy. If it happens (a way off yet I guess), it really would be a poke in the eye to Hasselblad. If Michael's comments about Victor turning in his grave are right (and I think they are), that would get him to a high speed spin.
So, for the moment, I'll stay with V series. Considering an H has now out of the window so that's one potential sale that Hasselblad have lost and, I suspect, not the only one.
All IMHO. Your milage may vary.