The answer is Yes if you are developing a Flex 3 application
to run on AIR, the Adobe Integrated Runtime. AIR includes a full
HTML renderer. But the answer is No if you are developing a Flex 2
or Flex 3 application to run on the Flash Player in a browser. The
Flash Player can only render a very small subset of HTML.
Unfortunately, including a full HTML renderer in the Flash Player
would hugely increase its size.