SciAm has an interesting article about the idea of Science 2.0 and how it seems to be slow to emerge. They suggest that the reasons range from shifting researchers from an attitude of competition to one of collaboration (OMG!) and celebrating the formative nature of the Scientific ProcessTM and not worrying that these informal notes are going to be treated the same as peer reviewed work.
If you think about it, there is a reason why the notebooks of the great researchers of the past have been so valuable. These books show not only the final work, but how they got there, something that Web2.0 is/would be great for science.
This matches up with what Johnny Lee was talking about in his talk. Get the information out there and start the conversations faster. This can have a secondary impact, just like online classwork and conference2.0, when there are strong connections made online, face to face time becomes far more productive.