Google worried? Doubt it.

For the first time, Google invited a handful of journalists to its annual Zeitgeist conference for advertising partners. Afterwards, Larry Page, Sergey Brin and Eric Schmidt held an on-the-record chat with us over sandwiches. They talked about their interest in wireless spectrum. They fretted that their biggest challenge (still) is managing their growth. They even showed their sense of humor. When I noted the unusual stability of the top executives beneath the ruling troika (as a prelude to asking if that stability would continue), Page quipped, “Emotionally or physically?” More seriously, he predicted continued stability and suggested a leadership training program is helping. (The word is that many of Google’s “economic volunteers,” a term that’s actually used within the company, will be retiring soon and that turmoil will hurt.)

The arrogance remains, of course. Schmidt held forth on how much the company is doing to address the concerns that caused Viacom (VIA) to take Google to court over YouTube’s policies regarding content it doesn’t own. He said filtering technology is in “various stages of rollout,” as if that were good enough. He said Viacom “rushed” into litigation. He obviously has the luxury of knowing the suit has done nothing to blunt YouTube’s advance.

On the subject of social networking, and Facebook in particular, they made it very clear just how interested Google is in getting into the game in a more meaningful way than its Orkut service. (Read my colleague Josh Quittner for a contrary view on how much Facebook worries Google.)

Bottom line: From my perch, these guys were cool as cucumbers. Genuinely relaxed, engaged and at the top of their game.

By the way, Google reports earnings Thursday. The company’s worth $200 billion. And its founders give off the vibe that they’re just getting going. As I’ve written in the past, Google’s management isn’t perfect. Its previous quarter was sloppy. My gut tells me this one won’t be.