Good job using the Search function! It really does work.
Sorry you hadn't noticed the answer to your question -- I had explained it in a couple of the threads, usually a one or two line thing talking about how VLC does not support certain proprietary (closed source) CODECs. This is the first time I explained a bit more of the "why", that it is a pretty nasty mathematical puzzle, determining what the proprietary CODECs are using for their processing algorithm; this explanation applies equally to WMV3, IV50, the various Real CODECs, basically any CODEC that's closed source -- it really is a "code breaking" exercise to reverse engineer CODECs, trying to determine the transform for a given set of source frames that results in a given set of output frames.
DJ and the other developers have probably hit this question enough times that it's burned into their minds ("Oh, no, not the proprietary CODEC question again"
A good question might be where to put such information (pre-canned answers). It's clear that a lot of people aren't reading the features list (there are many questions saying that "fourcc video CODEC designation XYZ is not supported", and the answer is "You're right, this is shown in the Features List), else don't quite understand the material there. There's also a FAQ for VLC, I believe, and there's a wiki.videolan.org, a user-contribution knowledge base to capture things like how-tos or information specific to VLC operation with a given operating system.
The developers have clearly been trying to get the information out, but it seems that there are a lot of repeat queries.
(I'm lucky -- I'm not a developer, but do a lot of research for work, so am comfortable poking about in various areas, using search tools, etc.)