I created a document to help people get started with XIFF.
Check it out, and give me your feedback:
http://community.igniterealtime.org/docs/DOC-2101
It covers where to look for the code (release and prerelease), setting up your environment to work with XIFF (Flash Builder and Flash), and setting up the examples to work with them.
Reply here if you have ideas for other docs and tutorials and I will try to get to them.