I would like to know what makes Flex more useful than Flash 8? Is Flex
basically replacing the Flash SDK? I looked into Flex a little bit and it looks
like it has an awesome integration of Flash and XML. I was also wondering if
Flex integrates other development technologies with Flash, such as PHP.

Currently I am working for a gaming company and would like to get Flex pretty
soon.

-Thanks in Advance :)

http://www.vectorflash.net

i think it is not "more useful" but both got different strength.