Eric Schmidt says Microsoft, not Apple or Facebook, is the biggest rival Google has right now.

"Bing is a well run, highly competitive search engine," Schmidt tells the WSJ's Alan Murray in a long interview. Meanwhile, it's "too early to tell," how big a competitor Facebook will be, he says. Apple is, "the extreme expression of a closed system, but also a partner."

While Bing is going right after Google's core business, we think Apple and Facebook are long term threats. Each of those companies are fighting for the next big thing.