I still don't have any idea about the backwards compatibility with Flex 3, after the new controls will be much more layout-customizable. One thing seems sure - porting apps to the Flash Builder will be more of a pain in the neck than porting Flex 2.0.1 to Flex 3. Thank god I'll be doing the Objective-C port

As for the code beautifier, after I've coded for only two years according to that convention, I got used to it and now it's much more difficult for me to read through code with C++ styling: opening brace at the same line, etc.
Cheers