Google Bears Growl New Tune

"We continue to believe Google faces considerable risks, including click fraud, mounting competition and the absence of revenue diversification," Kessler says. He also cut his price target for Google to $390 from $420.

The decline hasn't been enough for analyst Philip Remek of Guzman & Co. to change the sell rating he put on Google last year. He is now the only analyst who urges investors to unload Google shares, on which he has a target price of $310.

In an interview, Remek says he remains convinced he's made the right call.

"I still think it's overvalued," he says. "It's not as overvalued as it used to be. I don't look so crazy anymore."

Remek and other Google skeptics point out that Google must sustain hyper-growth rates to justify the multiple. Though Internet advertising spending continues to rise, that money may not all go to the search market, Remek says.

For now, these skeptical analysts will be overshadowed by their colleagues.

The latest analyst to urge investors to snap up Google shares is Denise Garcia of WR Hambrecht. In a note to investors Friday, Garcia says Google's prospects remain huge. She reiterated her buy rating and $455 price target.

"This is the time investors have been waiting for -- expansion into International Internet markets, multi-platform products, expanded advertising opportunities, and a serious step into the desktop software market," she writes. "It is also a time of considerable risk. While the faint of heart leave the table, we believe Google's vision is just getting started."