There is a release of the Winamp for OSX/MAC.
http://www.winamp.com/mac (http://www.winamp.com/mac)
excellent news for mac users since foobar2000 is not available ;-)
Appears to support the same formats as iTunes and that's probably about it. It also supports playing protected files, but I doubt it supports syncing those.
It appears to play tracks in the library in random order, and has no means of manipulating the contents of playlists, except for the automatically generated "Recently Played" list.
It's pretty obvious that the only purpose of this application, at least right now, is to synchronize with Android devices which are running the Winamp for Android application. Playing files locally is simply a "bonus" if you can call it that.