Unfortunately, the cowbell went the way of vinyl records and the Berlin Wall. If you listen to classic rock, you'll hear it a lot on old Grand Funk Railroad albums, and of course, BOC's "Don't Fear the Reaper" ?(Damn you Will Ferrell
!!). I think GNR were paying homage to the type of bands they listened to growing up in the seventies when they included it on "Nightrain"--kind of showing the world their roots, as it were. It's too bad cowbells are considered "cheesy" by today's standards. I kinda liked them.
To stay on topic: No way will the cowbell make an appearance on Chinese Democracy.