Hasselblad together with the Phocus software is phenomenal. Tethering works seamlessly and is very quick. The digital apo correction of Phocus corrects geometry, aberrations and vignetting to produce a result that equals or supercedes Leicas optics. Hasselblad is cheaper and produces fantastic high iso results with the h4d-40. The Leica has a very bad iso reputation, noise gets bad really fast above 160 base iso. Leica is a new system that might or might not survice. The MF market is a tough place with a lot of concentration dynamics in the last years. In the worst case the S2 might be discontinued if not many people jump onto the system and then you have spent a lot of money on a system with no development. Hasselblad uses a modular system which enables you to use a technical camera which in turn lets you use great wide angles lenses that are really superior and that let you stitch to produce huge panos rivalling finest large format prints. There's a healthy second-hand market for Hasselblad glass on ebay etc. whereas a Leica Lens alone costs a fortune. Professionals using the Leica complain about the long file transmission times and lack of workflow solution. If you want to upgrade it is not clear whether you can trade-in your syste - which I doubt, since it is the whole camera - whereas hasselblad and phase have extensive promotions and trade-up programs all the time to keep their customers in the system. So investment security is in the stars.
The Leica on the other hand has great optics with a heavy price and compact weather sealed body. The bokeh is nice. And it has a red dot.
If money isn't a constraint, and you don't care about a good tethering workflow or a technical camera, can live with the many uncertainties of the market or the future of the S line, and are more a casual enthusiast, the leica maybe a great choice.
If you want a proven system for a lot cheaper entry point with a good software that makes the results shine, than you should get the Hassy.
I have to say that I ordered a H4D-60 and own a M9. In my view the S2 was too expensive for what one gets and I wasn't sure about the future of the system. If I had enough money, I'd get both systems, as it can be nice to have such a form factor.
Regards
Paul