Unless they get some big patents with the property I can't see MS wanting this. I suppose they might buy it just to keep it from going open source and being a bigger competitor, but both sides of that seem unlikely to me.
but all the time that they have owned WinAmp, it seemed they did a pretty good job of not messing it up.
They basically did nothing. I recently went back to using Winamp for audio after many years of not using it, and it hasn't changed at all.