WordPress blogs will update in real time, via PubSubHubbub
There was already a Wordpress.org plugin that could activate PubSub, but WordPress has released a new and official version, called PuSHPress. There are no plans to make it part of the core codebase for WordPress.org, but a plugin is a good start.
The even bigger news is that PubSubHubbub has come to Wordpress.com, too. That's 10.5 MILLION blogs that just became equipped for real-time updates. If you're on Wordpress.com, you don't have to configure anything - the new service has been turned on for you already.