Pianoteq has come on in leaps and bounds in the last few years, however I still prefer Piannimisso http://www.acoustica.com/pianissimo/index.htm which as it combines sampling and modelling to my ears gives a more realistic sound.
Sound Modelling is the way forward however, and as I said a couple of years ago, within 10 years it will become the standard for producing sound, particularly as each new update appears to reduce the amount of CPU power required. (I was expecting a levelling of CPU power required, with the newer more powerful CPUs allowing more instruments to be produced simultaneously)
If I get the time I will download and try out WIVI this weekend to see how it goes.

Bill