I dont know the history of this but you can open HTML pages within an AIR application. This control is not available in Flex though and I would wish to have it. However the way to do this in Flex is mentioned in the comments below.
I can already see the benefits of this. I have not tried it out myself but soon I will try it. You need to use an HTML control to do this.
For a user interacting with an HTML control, the experience is similar to using a web browser with only the content window and no menu bar or navigation buttons. The HTML page content displays in the control. The user can interact with the content through form fields and buttons and by clicking hyperlinks. Any action that normally causes a browser to load a new page (such as clicking a link or submitting a form) also causes the HTML control to display the content of the new page and changes the value of the control’s location property.
Aalap Doshi 
Unfortunately, the HTML control is only available within AIR applications, and not Flex itself. AIR applications are desktop applications that (can) house Flex MXML.
You can accomplish the same thing today within a regular Flex application deployed to the browser. If you simply want to just launch a new browser window, you can use the navigateToURL() function (http://livedocs.adobe.com/flex/201/html/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Book_Parts&file=passingarguments_086_10.html).
Otherwise, you can use the Flex to AJAX bridge, and create a DIV that hovers over your Flex application to get the same results as the HTML control.
Thanks a lot.. I have been working on creating an application for both AIR and Flex and i guess i jumbled that up. However, it would be great to have it in Flex too…
Appreciate your response.