I feel the same way as bodegajed; I consider the way they're littering G+ everywhere to be very tacky, akin to something I'd expect from Microsoft or AOL. While I'm far from boycotting Google tools, it does make me want to avoid G+ entirely.
To be clear, though: I think this new bar in general is a usability improvement. The gray bar looked like ass, and having a consistent search box does make sense.
Google puts G+ in your searh results, with no opt out. G+ is fine on its own, but the creepy invasion across other products is annoying. Google used to be the classy alternative on the web. Now they are trying to out-mySpace Facebook.