When chatting on IRC, this popped up:
[23:04:21] <Foxtrot200> Does anyone here have stereo mix? Microsoft turned into a copyright Nazi and took mine away.
[23:04:35] <~Jimmy|BSB> Took it away?!
[23:04:49] <Foxtrot200> It wasn't in my sound card update
I don't know if this is true and if it applies to all Windows updates and sound card updates, but this is not good for those who use ePSXe + MTVMG/M2K. If they get rid of my Stereo Mix option, I can say goodbye to Music 2000 producing. Thankfully, I got an old sound card that doesn't seems updated anymore, so maybe I'll be immune. I also have no clue on which OS this applies. I currently use Windows XP SP2.
But in any case, I would recommend against updating your sound drivers anytime soon.
I think the reason for doing this is because people abuse the Stereo Mix option to rip music from Youtube videos, other sites and video games. (I myself do)