Daniel, I fervently hope that this never finds its way into a Debian package without an explicit --verbose switch. There's nothing more frustrating than being unable to reproduce a build failure from an autobuilder, and not having enough information to know if this is because it was a one-off failure, an already-fixed bug in the environment, or an incorrect reproduction of the buildd environment.
And libtool --silent sucks too.
While I understand the desire for less verbose build output, a good postprocessor for build logs would IMHO help more than a tool that just suppresses output -- once it's suppressed, you can't get that information back...