Ask HN: How can you leverage the Atom Syndication Format?

I've been looking into the Atom format and it looks like an under-leveraged platform. There must be countless great ways to take advantage of a regularly updated feed delivered to your inbox and plus, the format is so flexible.

Question: Is there any room on the Atom platform for something more radical than delivering news and tickers? Any way to make it more interactive, customized, cool?

Purposefully broad question. What's the best you can think of?