There isn't and more than likely there won't be.
The .bin saved of the replay is actually just in game data recording the moves you made, etc. That's why when you replay it in the game you can actually pause and move around just like a regular match.
What this means is that in order to convert .bin into a movie format on the pc it would require someone to remake almost the whole game for the computer. That's a little exaggerating, they can always find a way to transfer the file from the game to the PC and work with it there, but that's still a lot of work seeing how Wii homebrew is still just beginning.