When I last saw Williams, he had just returned from his honeymoon, a safari in Kenya. (In Africa, predictably, he twittered using his cell phone: “Touring Nairobi.” “Having drinks after a day of game drives and relaxing.” “Watching lions. Shhh.”) Over breakfast at a restaurant in San Francisco’s Mission District, he told me that he’s taking a few steps back from Twitter: he’ll sit on the company’s board but leave coding to the engineers and the day-to-day management to Dorsey. Before his wedding, Williams explained, he had spent a lot of time writing code for features and slogging through the daily maintenance of the service. Now he feels the company is in ­capable hands without him.

So do his venture capitalists, it turns out. Williams “seems a little more thoughtful and willing to live with ambiguity more than most of the entrepreneurs I know,” says Fred Wilson. “That’s a big positive, but it could be a big negative, too. It’s a positive because startups need to have ambiguity around for a while, but a lot of the time things need to be decided, which is why I think it’s good he’s letting Jack [Dorsey] run the company. Jack is probably a little more decisive.”

Now Williams says he wants to work more on Obvious, which, for him, is a different type of venture; he describes it as a kind of incubator for products that solve obvious problems. Obvious (which upon its founding in October 2006 absorbed Odeo) wasn’t created with a product or even a technology in mind; it was conceived as a company where ideas are fueled until they either catch fire or simply fade away. But as of our meeting, Williams was the only employee, and it’s clear that he doesn’t know how Obvious will operate.

Williams has some technological problems he’d like to explore, including his old preoccupation at Pyra: the question of how companies can communicate more effectively, both internally and with other companies. He has at least one person in mind to do some coding, too. Still, he seems uncertain how any solution could be turned into a product, let alone a viable business.

In fact, he tells me, he doesn’t have any solid plans. At the end of 2007, Williams finds himself in the same state that he has so often been in before: uncertain, without any irritable reaching after fact and reason.