There's an interesting article written by an ex-RISC OS user on OSNews. Michael Reed talks about what it would take for him to consider using RISC OS again. From the article:

In common with a lot of people who used to use RISC OS, I don't use it now and that is the focus of this article: Why don't I use it any more and what would it take to make me use it again? Of course, an article of this sort still has worth as there is bound to be some degree of correlation between my feelings, experiences and hopes in relation to the platform and those other people.

Link: The article