Dave Winer must be the only guy on the planet with a newsreader that can't handle Atom:

I was going to post a note saying that it would be better if you redirected to the new feed, but then I saw that your new feed isn't RSS, to which I ask -- why??

Do you want to lose subscribers?

Because that's what happened. I can't read your feed anymore Ted. I'll survive, but I will miss your posts.

I've never been a huge fan of Atom (although, as I posted awhile back, I fully understand why it exists) - but it's not as if it's hard to find a tool that handles RSS and Atom.