no need to worry about audio slender, just demux and remux the original. Remember AAC is a lossy format, so it already lost some of its original data and quality. If you transcode from lossy to lossless (AAC to WAV) you only increased the file size and then when you code that again to a lossy codec your going to lower the quality even more than it was originally.

Since all the Apple trailers are just using AAC LC at an acceptable bitrate its going to play on the N900 as is without any transcoding or additional loss of quality.

I have no problems contributing to your little thread, but your attitude is way off base, this stuff is not hard so no need to toot your own horn for knowing how to do it and infact you still have a lot to learn.