If you need fast flash sync and autofocus the H2 is the camera to get, especially if you wan't to use it now. There is no alternatve, because mamiya's leaf shutter lenses are not shipping yet, god knows when they will and which lenses will be available in leaf shutter versions and when...
I personally like the H2 with a phase back even if there are some drawbacks, but there are with every sytem. I would love to see phase backs for the Hy6, but even if a dealer told me it will be coming, I don't believe in that anymore. And the lack of a complete af lens line up fot the hy6 is also bummer for that system.
Some people need a 28mm, so if that is the case, H2 and phase is a no go combination, but I'd rather use a cambo or horseman or similiar tech camera with an h mount for those real wide angel shots.
I wouldn't worry to much about this open/closed system discussion, the H2 is a fine system which will be around for quite a long time, even B+H started selling new H2s again (where ever they get those from...), there is already quite a huge used market and it is available almost everywhere around the globe in rental houses. If Hasselblad gets their backs up to par with phase, maybe a H4d, H5d becomes a nice upgrade in the future and you will be able to use all your lenses...
cheers,
martin