TC: No offense man, but you are making yourself look stupid. The people you replied to did indeed read your post.
Your knowledge of video formats and replays apparently is limited to file extensions. Let me spell it out for you.
In order to save space, Brawl replays will probably just contain movements and random seeds so that the entire match can be replayed from the Wii. If you save the replay to an SD card, it will be in a file format your computer will not be able to recognize. This file will not be convertable without a full emulator of SSBB containing all the texture, model, and animation data. Although it would be awesome, this will not likely happen.
You will still need a capture card or a camcorder to record matches. The handy thing will be that you can just play back and record to your computer after the fact, rather than having to record the game as it's in progress.
I hope this helps you understand what people are trying to say here.