As I've written a number of times on this blog--I didn['t realize how many until I Googled it; see, for examples, here, here, here, and here--it's only a matter of time before the Antitrust Division declares Google's manifest superiority has become illegal. (They won't say that, of course. But substantively it will be the same.) Here's the latest suggestion that I will be right: "Why Is Obama's Top Antitrust Cop Gunning for Google?"
If it pays lip service to "potential competition" the Antitrust Division may want to look at "Cool Search Engines That Are Not Google".