Since the release of Weld and Java EE 6, there's been a heap of activity in the Weld user forum, and especially a lot of questions about problems related to framework development. You can do some kinds of generic programming in CDI just using managed beans, producer methods and InjectionPoint. But if you want to get serious, you're eventually going to have to embrace the portable extension SPI. Here's a couple of examples of how people are using this SPI.
Steven Verborgh has written a nice tutorial showing how to implement a custom JSF view scope for CDI. Henri Chen has integrated the ZK framework with CDI (hopefully other web frameworks won't be far behind). Matt Corey has been experimenting with environment configuration via JNDI.
Meanwhile, I've been working on compiling user feedback into a list of enhancements to the SPI. We plan to roll the most important items into the first CDI maintenance release.
UPDATE: for completeness, I should also link Pete Royle's Quartz scheduling extension.
I tried to use weld in my test JSF application (http://www.agost.ru) . I read some articles about using weld as event bus and so on. But I was not able discover a way to improve my project seriously by weld. My conclusions are:
Plus: Little bit shorter code Code is more beautiful
Minus: One more heavy library in project Increase GAE cold start
Would you be able to recommend some links to read about weld and JSF. For example Google shows strong support of MVP pattern in GWT and demonstrates how application could be improved by Guice and Gin. I suspect weld could be used like analogue.