It looks like we still might be rolling out the pages, but the front of Adobe.com lists oodles of Flex and Adobe AIR content!
For more information on Adobe Flex 3 and Adobe AIR, see: http://www.adobe.com/go/flex/ and http://www.adobe.com/go/air/.
Also, go check out the Developer Center for lots of articles, Flex Developer Center and Adobe AIR Developer Center.
You can also find Adobe Flex Builder 3 (Standard and Professional) at the Adobe Store now, Adobe Flex Builder 3 Standard and Adobe Flex Builder 3 Professional.
Also, for more information/opinions, check out the following Adobe blogs:David Zuckerman: Does this mean I can take a vacation?Ted Patrick: 123 Go!Flex Team blog: Its On – Flex 3.0 and Adobe AIR 1.0 Are Here!Deepa Subramaniam: WE SHIPPED!Matt Chotin: Flex 3 and AIR 1 are a GO!Peter Farland: AIR, Flex 3, BlazeDS, and a new Adobe Open Source site!Narciso (nj) Jaramillo: Flex 3, AIR 1.0, and Adobe Open Source are live!
