It is great, that it possible to implement POS.
As we all talk about promotion, implementing POS can be something big with a lot of interest.. like 2nd big start or second level of coin evolutioning. Of course, for now almost everyone can mine some coins and POW is more than enough, but in the meantime, when cap is rising so far, POS can be good locomotion for stimulating people to buy amounts of PRT. Well, they can do it anyway, but, you know, when you bought some money and they work for you - it`s a good illusion and NXT coin all depend on it. So, such stimulation in future can give us best from both worlds. Also, there is none, or a very few coins with CPU only POW + POS. So, it is good to be unique $)).
Also, with wallet implementation, people are right - better less changes and frequent updates. People think that something happens - it seems, this psychological "illusion" support great beliefs in them.
And kids )) IT would be nice something, that let kids to use PRT... For example - parents buy coupon code in app store with some prt for use in kid`s application.