I've been thinking about and researching how an institution can share its data, documents, and other content.  Obviously your data and content is already exposed via the web, but providing the data in a more structured way allows more users (both internal and external) to manipulate the data in interesting ways, for example in mashups.  There seem to be a few ways to share data from an enterprise with a lot of content:

• Straight RSS/Atom.  Although straight RSS/Atom (with no custom extensions / namespaces) may not be that interesting, it's obviously a useful way to get your content out there.  Typically straight RSS/Atom is fairly time-based and might in effect show some history (news items like "John goes to work" and then "John goes home") rather than some state (like "John is now home"). 

• Common repositories / services such as Swivel and StrikeIron.   Rather than exposing your data/content directly to the outside world from your site/servers, you can use an intermediary.  Swivel allows users to create their own graphs on fata from either official sources or any user-supplied data.  StrikeIron is built into mashup editors like QEDwiki, and also has built an extension to Excel to call their services.  You probably would want to provide data to these services through an API of your own, but you could get started with Swivel for example by directly uploading the data. 
• Specialized XML formats for particular types of content.  Examples include OpenSearch for search results and SDMX for statistical data.  These specific XML formats both allow a level of sophistication for people specializing in your type of content and allows tools built for this type of data to consume it.  This fits in with the following item, which, for historical reasons may or may not be XML-based. 
  
• Institution-to-institution services.  Sometimes you need to provide a point-to-point interface with another institution.  In that case, you may need to support all sorts of unusual formats and delivery mechanisms.  Hopefully you could leverage your various systems' web services to just transform the data into the formats you need. 
• A common API that your institution follows across all types of content.   This one is the most interesting to me and one that I alluded to in my previous post on interaction publishing.  Especially if your institution has various repositories, one possible approach would be to slap up a page that has links to the different instructions for referencing each.  But, to make access as easy as possible, a common API with consistent parameters that can be queried against all systems would be preferable (for instance, queries such as "give me all your documents and data on Chad" via url requests like http://xml.example-domain.com/apis/type=docs,data&country=td).  Potentially the returned XML could be in a simple format such as RSS extended with a custom namespace (so that other tools such as Yahoo Pipes, and even feedreaders, could easily consume the data).
• Microformats.  Probably most useful to future browsers or other tools like the Firefox Operator extension (or for services that crawl sites such as Google), microformats allow you to just change your existing HTML a bit to expose very common types of data like address and calendar events.  For example, instead of your HTML having "100 Main Street, Anytown, USA" it would be marked up as "<div class="adr"> <div class="street-address">100 Main Street</div>, <span class="locality">Anytown</span>, <div class="country-name">USA</div></div>" and then define the CSS to show it as you wish.  For example (with sloppy CSS):
  
  100 Main Street

  Anytown,
  

  U.S.A.

  See how this page appears in Firefox Operator (also notice the tagspaces):