The betting is that a Google-ITA combo would transform Google into a major travel-metasearch player and with that kind of threat to Kayak, coupled with all of the uncertainty in the air, Kayak would be hard-pressed to price its IPO high enough to get the kind of return its investors envision, given its roughly $800 million valuation.
Read the full story at http://www.tnooz.com/2010/04/30/mobile/google-ita-chatter-puts-kayak-ipo-on-back-burner/