There is a growing body of evidence that blogging, chatting etc. are helping children to improve their literacy skill.
(see e.g. a recent article from BBC).
Comforting news for worried parents...now we just need to learn the new language 
and reassuring news for people working with mobile and social learning technology. We might be on the right track.
I have been teaching for many years project based courses at the university and I see that pre- and elementary schools are facing similar challenges. When we go beyond a notion of learning as acquisition of factual knowledge or of specific techniques, we are facing difficult questions like: what is a good learning experience? How we promote growth of individuals and of the complex social networks they belong to? How do we create contexts to promote learning? How do we assess learning?
Difficult questions...it is much easier to think that we can measure learning with "universal" tests of some type! But can we? How dangerous is it to refuse addressing these challenging questions?
testing, benchmarking, ranking, etc. etc.
If you feel uneasy with these buzzwords and you think they do not tell the whole story, you might find interesting the book "Beyond quality ...". Though it refers mainly to early childhood education, its message is much wider.
Some food for thoughts ...In more than 40 years the pre-schools of Reggio have never been evaluating themselves against some easy measurable predefined criteria, nor they have "tested" their children. ...Still they are an example worldwide.