One big trend in Web 2.0 is embedding. Embedding means showing a piece of content from another site. An example is showing your librarything items or your delicious tags on your blog. Every web 2.0 site is offering badges, embedding HTML, icons and other stuff to put somewhere else, or at least they should! Most people use them on their blogs but of course they can be used on all sorts of places as long it is HTML. A nice example is the blog of euan semple, showing all kinds of stuff from other sites!
Embedding is not entirely new and looks a lot like portalfunctionality. Portals have been around for sometime. Embedding, I think, has more future because of its simple nature. Embedding does not require the showing site to have any functionality at all. Portals and portlets do require functionality on the showing site.
In enterprise 2.0 people will want to embed functionality and content from inside the firewall and outside the firewall on one spot. This is consistent with the vague-ing border between personal- and worklife. The other thing is that is useless to develop some functionality inside the enterprise that is for free on the outside! Unless there are some security issues of course. Why develop your one video sharing functionality while you can embed a youtube video on your internal wiki?
Embedding is a perfect example of innovation in assembly. A concept introduced by Dion Hinchcliff. Another example is open API what facebook is dooing right now.