New York entrepreneur Jeff Dachis has landed $50 million from Austin Ventures to fund a comeback — but not as a New York entrepreneur. He's trading a 212 office line for one in the 512, to launch a new company promising to bring the Web 2.0 revolution to businesses. Despite the change in venue, and the new version number, that sounds eerily like the premise of Razorfish a decade ago — the digital consultancy which Dachis launched, and whose value he watched plummet from $5.5 billion at the height of the 2000 bubble to $8.2 million in a 2002 fire sale. So what is Dachis's company, if not simply Razorfish 2.0?