What effect would that have on music as a whole?
No Back In Black? Pretty big butterflies in the rock community, but AC/DC still has a legacy at this point, so anything Angus and Malcolm do will be given attention no matter what, at least for the next few years. Hell, Angus and Malcolm could even end up working with Brian Johnson, just not as AC/DC. So in some sense, the sound will live on, as AC/DC have never been known to experiment much or to be really complex musicians. Krokus would likely see a bit more popularity as a result of there not being any new AC/DC music to compare them too.
Personally, I'd love to see a project involving Angus and Malcolm Young, and Ronnie James Dio after he leaves Black Sabbath in '82.

I doubt it would happen though.
