On his blog he said, "This was a very hard decision, and not one made lightly. I have always enjoyed my work, and still do -- everything from MTS-2 to Sun Fellow to Oracle VP. I love the people I work with and the technology we've created together, which is why I've been doing it for so long. But I have always wanted to try doing a startup, and recently identified an opportunity that I just can't resist. (We are in stealth mode, so that's all I can say for now.)"
Bonwick didn't say he was leaving because of Oracle's takeover of Sun, but since the acquisition, there has been a steady stream of talent exiting the company, as well as, open source projects.