if Sony will make something, it will be for a major market I assume. So if they bring out something like that, it won't be only pro orientated. and of course Hasselblad will bring out a new camera, so will Pentax and PhaseOne. As long as the companys won't die, there will be a new camera. At one point you got to invest in 5 years down the road you will think about reinvesting...never ending story :-)
no matter what, the current tools we have to make photos is awesome. if you think back what happened in the last 5 years. For me, everything what comes now is just Bonus. There isn't anything that is missing to make great photos, imho. with a 100MP back, I got the feeling that even 8x10 is obsolete. For me though, a 100MP back would be a too big workflow (storage, computer power, processing time, etc)...if I need something like that, I will rent it.