E-Learning 2.0

There's an interesting article about the Web 2.0 movement and its implications on learning. While in the past, learning was focused on class-specific documents augmented by additional tools such as discussion forums, we now seem to head towards the opposite - a kind of free-flow learning, heavily characterized by blogging, using wikis and emerging technologies in mobile settings (such as podcasting). All this sounds very exciting, but I am wondering whether there is any evidence for real collaboration geared towards building up knowledge in social groups. If Web 2.0 is an attitude, what is e-learning 2.0? Is this interaction between learners and systems (turning their users into content producers - what's going to happen to all this content), or does this really support social exchange? Or, to put it differently: in what sense should E-Learning 2.0 be able to fulfill what traditional E-Learning hasn't?