WordPress now supports rss.js.

What this means is that you can access the flow of new posts from a JavaScript app running in the browser without any special server software. It makes it more efficient while preserving know-how already in developers' brains. Why have a new way of doing something we already know how to do? Exactly!

This also means interop will be easy, and makes it possible to have new blogging tools that are compatible with WordPress in new interesting ways.

May not mean much to end-users. By the time developers deliver features based on this stuff it'll be baked into the platform ten levels below the user interface. But that doesn't mean it's not important.

It's like having a new subway tunnel in NYC. Eventually we'll be able to use it, and when we do it won't look like this. But we'll be able to get places we weren't able to get to, so easily, before.

It's a good thing.

PS: I don't think this is available (yet) on wordpress.com.