Kylotan, thank you very much for your reply! Actualy this is already a disussion I was hoping for . I'm not a game-dev professional myself, but I'm interested in it and would like get a clear picture of what is realy going on. Without considering points of view of other competent people I will be just blinded by my own believes that do not necessarily reflect reality.
I was talking specifically about mobile games, and it seems to me that most people got used to approach of paying for the whole game at once, and now the focus is changing to in-game purchases (as discussed by the article at forbes.com mentioned above).
Probably I also had to be more specific when talking about pros/cons - I meant particularly the developer's (or publisher's, if applicable) point of view.
P.S. many thanks for links - I'm going to check them soon.