Joseph Scott has a post on the main WordPress site that explains that they are now supporting the two enhancements that were announced here on October 16.

What this means: Now any aggregator that wants instant updates of WordPress sites can have it. It was an issue for complex sites like Google Reader, that's why we enhanced our apps, so they could hook into rssCloud and provide instant updates to their users. If you use Google Reader or My Yahoo or Bloglines, tell them you want rssCloud support so you can get instant WordPress updates from sites like CNN, TechCrunch, GigaOm (and of course) Scripting News!

WordPress also fixed a problem that could prevent RSS feeds from reflecting the change immediately. That was a problem because sometimes we'd receive notification that a feed had changed, and then would go read the feed only to find that it hadn't!

Many thanks, once again, to the great people at Automattic.