FeeLitFresh

RSSCloud is an element which is always been present in the RSS 2.0 spec but has drawn new attention with the rise of interest in the Real Time Web.
This is like the difference between checking your email every once in awhile and using a Blackberry to get new emails pushed to you as soon as they arrive. The subscription method of RSSCloud works more like Instant Messaging than the old method of polling feeds for updates each time you fire up your feed reader.
So while Twitter, Facebook and the major search engines battle it out in providing real-time information services to web users.WordPress has announced that all blog on the WordPress.com and blogs that will install the RSSCloud plug-in will soon have instant updates published to any RSS readers
Google Reader, the dominant RSS aggregator on the market, began a limited implementation of a related protocol called PubSubHubbub last month.
There is currently only one RSS aggregator that supports RSSCloud, Dave Winer’s brand-new reader River2. That will probably change very soon