Tis a fine choice indeed. Are there really that many people who don't know who he is? (and yes, some might only know him if you said "Doogie Howser," but I'd wager it'd be about the same percentage who would only know Angela Lansbury if you said "that snoopy Murder She Wrote woman.")
And non-theatre-fans will never watch the Tony Awards no matter who the host is. I don't particularly care for football, and I highly doubt I'd tune in for a game even if I heard Maggie Smith would be doing the play-by-play. (ok, maybe I would for a few minutes

)