The basic idea is merge to the same server contents coming from:
- internal sources (accounting, trouble ticketing, exiting document management applications, other data bases: we should be able to get a feed from any internal app)
- k-logs (every member of the group has one)
- external news sources (general news, weblogs, specialized sources, scraped pages)

Centralized aggregators should not necessarily mean that every user has to read all feeds. There should be both the kind of personalization allowed by personal aggregators (deciding which feeds to subscribe to) but also added vaue services that would allow users to discover additional sources of information and anyway give different relevance to different kind of information snippets that are displayed on the page.
Paolo has put it succinctly. The aggregator becomes the organisational hub gathering information from all sources and using personalisation and intelligence to filter & recombine information in useful ways before presenting it either as views or as feeds for other consumers.
[Curiouser and curiouser!]