This feels a bit backwards to me: passing `{}` behaves identically to `{ :verbose => true }` but `{}[:verbose]` and `{ :verbose => true }[:verbose]` return different things.  Instead, I'd prefer to see a `:silence` flag (or similar) that defaults to `false`, as `false` is the more natural value for a config option you haven't passed.

Alternately, we can keep `verbose` and have it default to `false` -- we'll just have to pass it at the call site here in rspec-core but that's fine.