Why does the mac version of miro use Flipformac instead of vlc?

The new osx beta of miro is much better, but I still see the flipformac progress bar for sometimes up to a minute on some wmv files when I select them to play (which also happens in other Quicktime based apps. Why don't they use the VLC engine instead of the flipformac one? It seems just as robust and it never has to wait to start.