I think it's a great feature. "I remember reading something about X. Was it on Google+? Was it a blog post? Was it in my email?" Now you don't have to hit a number of services. I think your assumption, even for you, that you remember the source of a piece of information is faulty.
I search email a lot, and having access to it from a standard browser address/search bar is much shorter.
I search email a lot, and having access to it from a standard browser address/search bar is much shorter.