CNET editor-at-large Michael Kanellos is leaving for a post at the Oakland office of Greentech Media according to a tipster. Kanellos has been with the company for 12 years, and recently added cleantech stories to his beat. While no editorial staff were handed pink slips in the last round of CNET layoffs, Kanellos may have taken a look at the green tea leaves and left before the company had the chance. As for the promise of cleantech media? We suspect he's hedging his bets. Greentech is more an analyst shop than a publisher, and enviro-mad VCs who pay for research reports are a surer source of revenue than advertisers.