Not bye bye for me, but hello to new options. I agree we're living in exciting and interesting times for camera development but I'm certainly not going to buy anything new for a while to see how the dust settles and see how these systems develop and what lenses they make.
Generally, I love Medium Format and use it quite a lot but where I don't feel I've ever bonded with it is lenses. I love the Zeiss 110 Planar and the Contax 80 f2 and some of the Leica S lenses, but generally, for my preferences 135 lenses like the Zeiss Otus, the 135 apo-sonnar, Leica M lenses jhave particular qualities I like. It's quite frustrating because I need the quality of Medium Format files but generally I'm not keen on the Hasselblad HC lenses, and the Phase One lenses, though high quality I don't gel with so much either. if Phase dropped an 80mm f2, I would feel like I had more direction on where I wanted to head.
The X1D I like but, the lenses are going to be slow. The Fuji might have some more love but the Fuji Blad HC lenses, I'm not a fan of. The out of focus and bokeh is nothing I like at all.
I do feel that cameras like the D810, and to some extent the 5DS R, are probably better places to focus on for future as they close the gap further on medium format. Medium Format will always be king because it has the physical advantage of better quality but judging by the similarities between an a7r2 and a Phase One P45, it's going to get interesting as things progress.
The Leica S seems like a perfect balance to me, I love the look of the lenses. To their credit they are the pioneers of this sort of camera, IMO. Too bad it's crippled with reliability issues and has been stuck on 37MP since 2008. I saw a comparison with the 5DS R and the Canon came out very favourable in some keys areas.