Adobe Labs is your source for early looks at emerging products and technologies from Adobe.
http://labs.macromedia.com/

Macromedia home site.
http://www.macromedia.com/

Flexcoders group on Yahoo. Enterprise RIA Development with Macromedia Flex.
http://groups.yahoo.com/group/flexcoders/

Macromedia xml news aggregator.
http://weblogs.macromedia.com/mxna/index.cfm

Flex forum on macromedia.com.
http://www.macromedia.com/cfusion/webforums/forum/index.cfm?forumid=60