Leading Enterprise 2.0 guru Andrew McAfee (he coined the term a few years back, to Davenport's disgruntlement) has taken a look at some potential implications of Enterprise 2.0 in law firms, should they move away from a billable hour-based business model. He suggests that attorneys and others at firms could be given credit for engaging in collaboration through Web 2.0 tools such as wikis, blogs, mashups, and prediction markets. Moving away from the billable hour could help knowledge workers contribute productively "in the flow", instead of having a separate track for KM or collaborative activities.
I agree with McAfee that succesful adoption of Enterprise 2.0 technologies will require embracing these tools "in the flow." Having separate silos for knowledge sharing work and "normal" work can be a recipe for ignoring the former. The most succesful knowledge sharing tools I've seen, such as West KM and Interwoven, rely on a tiny amount of input up front, but only such input as is demonstrably to the user's benefit. For instance, a user will put in a matter number when saving a document to a DMS because it helps the user find that document again when they search by matter. Doing so also lets us KM types bring over a lot of other context from other systems for that matter.
I'm not so sure that law firms will need to move away from the billable hour in order to be able to achieve some of the benefits of Enterprise 2.0. Picture a wiki that is used on a particular matter team's work, with RSS feeds and the entire team always able to access the deal or litigation status, history, and context. Or a blog by a practice area manager used to update attorney internally on the latest decisions, briefs, and practice area numbers. Even complicated systems may be adopted, if it is easy to prove to both the line-level users and the supervisors that the benefits will greatly outweigh the hassel.