Events, Eventing and Notification
Werner Vogels has a nice, high-level overview of WS-Eventing, WS-Notification and WS-Events (I never even heard about the last one).
This is a single archived entry from Stefan Tilkov’s blog. For more up-to-date content, check out my author page at INNOQ, which has more information about me and also contains a list of published talks, podcasts, and articles. Or you can check out the full archive.