I posted this as a comment to Teds but wanted to put it here as well:
What's interesting about Wallop is the comments I read after they presented it at PDC. Someone referred to it as a "bliki", a cross between a Blog and a Wiki.
A Blog really is just like a personal Wiki, although arranged by date (or recent topics). The Wiki obviously brings much more to it.
When comparing them to learning management systems and the like, a Wiki is almost always the better choice, because of the automatic links.Instead of having to "blog-roll" Ted, I could simply type TedRoche and it would automatically link me.
Once again, I think Microsoft will be attempting to leap-frog the technology. You can read more about what that entire Social Computing group is doing here: http://research.microsoft.com/scg/
Some of the stuff has already been done but others look very cool!
Ted's Radio Weblog