"The new design retains many of the feature changes we made in November that proved popular, including a unified search box and Google+ sharing and notifications across Google. The biggest change is that we’ve replaced the drop-down Google menu with a consistent and expanded set of links running across the top of the page," explains Google.
The black bar doesn't look that great in Google's redesigned interfaces, but it's more functional than the "invisible" menu hidden behind the Google logo. It's always a bad idea to hide important navigational features, even if they clutter the interface. When you have to explain basic features because they're not obvious, you've already failed:
{ Thanks, Cougar and Matan. }