Just to prove a point, I flooded a couple of them and found that sure enough, nobody can really keep up. It's even more annoying when they don't even support persistent HTTP connections.
So --- I decided to turn things on their head and make them get data from us. If they can't keep up, it's their loss.
Prototype: (not its final home)
$ telnet danga.com 8081
GET /atom-stream.xml HTTP/1.0<enter>
And enjoy the never ending XML stream of Atom feeds, each containing one entry. And if you get more than 256k behind (not including your TCP window size), then we start dropping entries to you and you see:
<sorryTooSlow youMissed="23" />
I think soon we'll get TypePad and perhaps MovableType blogs all being sent through this. The final home will probably be on a subdomain of sixapart.com somewhere, including documentation better than this blog entry.
And yes, I'm sure my Atom syntax is bogus or something. I spent a good 2 minutes on that part of it.