I've just tried Adobe Alchemy, a preview tool that uses LLVM to compile C++ to actionscript. It still has some touching up to do ( see my posts here and here and my experience with alchemy ), but it is very promising. There is even someone working on porting Doom to flash ( here ). This finally opens the door to truly portable binary files. One can now distribute C/C++ applications to anyone as swf files, without requiring the user to compile them. Now we can really have a web-based OS ;) ( kidding ).
I hope LLVM grows much more, and solves all of the worlds problems. What will LLVM look like in 5 years? Front-ends, back-ends, optimizations, JIT, etc., I don't see the limit.