Yes, but it's hard to look past the classic Winer huffery lining the
edges. I believe he's been out-engineered by the whipper snapper
engineering duo at Google (Brad Fitzpatrick and Brett Slatkin) who
built pubsubhubbub as a bench project.
Pubsubhubbub (can we just say PSHB?) builds upon the smart publication
specs from RSSCloud, but adds a framework for real-time client
notification. You could do this with RSSCloud too, but the PSHB option
is more full service. And there are already a few implementations
cropping up in the wild.
Here's a blog post itemizing a feature comparison:
PubSubHubbub = rssCloud + ping ?
http://jy.typepad.com/jy/2009/07/pubsubhubbub-rsscloud.html
Marcus