Does anybody have any information about the .WV2 file format that the GOG version of Outcast uses for the music tracks? Preferably I would like to know if there is a way to convert those to other audio formats and back again. I've tried several different multimedia players and transcoders, and none of those have been able to figure them out.

nope, but you can get the songs from the original soundtrack of the game.

I am well aware of that, and it does not help with my intentions.

You can find the files here (end of the page, mp3 96 kBit/s):
http://outcastii.free.fr/www/eng/index_eng.php?url=download.html#patches

No problem to change to .wav or others with i. e. Format Factory.

Edit:
sorry, back to .WV2 ist not implemented in Format Factory

Edit2.
just saw, that the same files exist in my gog-account with 128 kBit/s.
Which files do you mean? The files in the installation folder?
(I can't look for that, because the game is not installed at the moment)

Just one question:

what is the sense of your plan, to convert to other format and "back again"? Specially "back again" i can't understand ;) And is the WV2-format such better than the mp3 quality?

My foremost thought was to check the Ulukai Dance track and see if that playing so late in the ending might be due to there being actual silence at the beginning of the track. I checked that track on the original CD, and there it does indeed have over a minute of silence for some reason.