If I were you, I would go the Hasselblad upgrade path and vote for a H4D60. Doing so, you will get most value for your money (which is the reason of course why these companies offer the upgrades in order to keep their customers
) and keep you on the save side for the next 2 years before something newer and maybe upgrade worth is coming!
The decision to wait and see WRT S system is definitely the right one. My stomach or what else internal organs tell me, that the release date will further drop and even if the manage to ship some units in January a kind of predictable purchase will be not possible before autumn 2010. WRT S glass same feeling plus you cannot count on the availability of say 80% of the S lens lineup within the next 2 years. That makes full system availability 2012 in my opinion and then - I can predict for sure - the current S2 will be completely out of date and fully overtaken by 35mm DSLRs (or at least equal level) and completely left behind the 60-80MP backs available by then from Phase and Hasselblad. So you can call this generations behind - generations in terms of digital evolution.
Will they have a S3 as answer for that? Maybe, maybe not. But even if they would do this homework then the S3 would have a maximum of 55MP (or similar range), while you would be in the 80MP plus area with Phase and Hasselblad.
I am also sure that both Phase and Hasselblad will do their homework to upgrade and complete their lens lineup to make it fit the next generation high resolution backs, so the argument of just Leica glass can be as good is no longer true.
I for myself decided - after almost 9 months of research, testing and trying and reading all material and reports I could get hold of in different forums, mainly here in GetDPI I must give this compliment - to go for Hasselblad. It could have been Phase if they did not screw up the final pricing, but from the product both vendors were finally equally appealing and also readiness and openness (even if only internal) of their systems in terms of upgradability.
Deciding for Hasselblad allows me an upgrade early next year to H4D60, I will add 1 or 2 more lenses to my lineup - 28, 35-90, 100, 150 or 210 - and be a happy shooter. And if I desire so I can expand with any tech camera and their legendary glass, which I still have to prove if it delivers better results for me than the system I have by then.
And in 2 years - who knows, upgrade to the H5D80 ???