Browses are essentially categories / sitemap layer on top of variety of documents / material that gets accumulated from various people. For examplt, Open directory project is a group-based browsing system created to capture the most useful links out there.
The information accumulation may happen under wiki systems, forums, weblogs, newsgroups and sometimes through emails.
While most people submit information, very few people create browsable interfaces for that information. Browses take the user to specific information, unlike searches and news (i.e. tracking changes) interfaces to the same information.
Creating "browsing" on the information will work for specific use cases - such as "What a new person joining the project should learn". In essence, this is a context. Some contexts have long-time validity (like in project-induction process) and some others have short time (such as proposal making).
Since browses are for specific activity/context, the overhead in creating a browse in advance needs to be carefully examined. For example, if a group starts to collaborate on a new process, members should probably put browses to identify "must-read" information by all members, to give context to the work, and to identify relevant documents within and outside of organization.
So it doesn't make sense to have "master browse" for information within organization, the people can browse through a list of activities, and then access the browsable information within that context. It also helps in why that information was relevant to that activity.
When a specific activity is started, how quickly you can let other people (not formally part of activity) to reach you with helpful content? Obviously, you would also like to filter the incoming information - typically this is based on relative expertise of the person is giving the information. In large organizations it would be very difficult to know real expertise levels. That is when you go look at the weblogs maintained by those people.
But it also helps to know "What is happening in organization now"; that is the only way the connections are made. (And that also explains why a canteen or coffee corner is strategically essential to any organization!). You require news like interface her: Which people are in news? What events are happening? What topics are being discussed? Here is an interesting tool: k-collector from evectors.com. It is an interesting approach for presenting information from weblogs (and possibly, from wikis as well): In terms of "What", "Where", "Who" and "when" boxes that give overview of what is happening in your organization (or in a community where the server is hosted). This is probably achieved by tagging appropriate information with weblog entries: such as people, places, events and so on.
The "optimality" of social-expertise and experience exchange tools will continue to be refined, and I hope some set patterns emerge giving a clear idea of what tools will result in better ROI.