Change is coming over at Twitter too

Twitter executives Jack Dorsey and Evan Williams are switching places.

According to a post on the microblogging service's official blog, co-founder Williams will resume the helm of CEO from Dorsey, who will take over Williams' position as chairman of the board.

"We're entering a new phase now and there are new kinds of challenges ahead. Healthy companies acknowledge the need for change even during the best of times," Williams wrote in the blog post. "As Twitter grows both internally and externally, we took a good look at our path forward and saw the need for a focused approach from a single leader."

Translation: It's time to get real.

Twitter is growing fast, and closed a $15 million funding round in May. It weathered an engineering shake-up this spring and has managed to largely overcome its well-publicized server problems. Plus, Twitter has become a staple in tracking political zeitgeist--cable network Current TV displayed real-time "tweets" onscreen during the presidential debates.

But Twitter still remains Silicon Valley's poster child for hyped companies without revenue models. With the financial crisis continuing to unfold daily, that simply isn't acceptable.

We've heard whispers about Twitter's ideas for making money: that the company has thought about offering premium accounts for businesses that want to use it as a marketing tool, for example, or that its acquisition of search tool Summize may start to play into an advertising model.

But all this is tentative; the fact of the matter is, in this kind of economic climate, Twitter needs to shape up. Whether this was the result of investor pressure or a voluntary decision by Dorsey and Williams still isn't certain. At least on a superficial level, this makes sense. Williams was a more prominent "face" for the company anyway, whereas Dorsey tended to stay behind the scenes.