Here's a nice writeup explaining when, how and why Google Chrome talks to Google.com:

Preventing paranoia: when does Google Chrome talk to Google.com?

Featuring this great quote referenced from a NYT article (emphasis mine):

Will Google ensure that its own services run better in Chrome than in other browsers? Is this part of Google’s great conspiracy?

That’s a no and a no. Chrome is open-source, meaning that its code is available to everyone for inspection or improvement — even to its rivals. That’s a huge, promising twist that ought to shut up the conspiracy theorists.