Time to switch? The technorati are saying yes:

I just switched the default search engine in my browser from Google to Bing. And if you care about working efficiently, or getting the right results when you search, then maybe you should too. Don't laugh!

It all boils down to Google attempt to force "google+" on everyone. As someone who rarely (around every 8 months) pops up onto facebook, I'm not too concerned with Google+, but altering search results to push the service over twitter (which I use about once a week) does seem like a bad idea.