Lauren Zalaznick is leaving NBCUniversal. So goes one of the TV’s most high-profile executives and No. 48 on the 2012 Fortune Most Powerful Women list.

In fact, it was a matter of when, not if, Zalaznick would leave NBCU. She lost her preeminent position there when CEO Steve Burke’s shuffled his senior management last February.

As I detailed on Postcards, Burke put Bonnie Hammer, No. 33 on Fortune‘s MPW list, in charge of all of the cable entertainment channels in parent Comcast’s media empire. As Hammer advanced, Zalaznick, 50, ceded control of two major networks, Oxygen and Bravo. That stung particularly because Zalaznick built Bravo from a tiny niche cable channel into a major, high-margin network for affluent audiences.

Since the February shuffle, Zalaznick has been EVP in charge of digital strategy across NBCU–a challenging task for anyone, but particularly an anti-establishment exec who started as an independent filmmaker, says her motto is “Create, Innovate, Have Fun, Win,” and proudly resists a C-suite persona. With an office—colorful and quirky, like she is—a few steps away from Burke’s on the 51st floor of NBCU’s Rock Center headquarters, Zalaznick has been noticeably uncomfortable there and restless to get back to running something.

Zalaznick, whom I recently interviewed at Fortune Brainstorm Tech about TV’s future, has been advising a couple of tech companies and investing in startups that combine content and technology. Don’t be surprised if she moves on to a job running one of them. Meanwhile, her exit from NBCU means expanded power for 39-year-old Cesar Conde, the president of Spanish-language Univision Networks who earlier this month joined NBCU as EVP in charge of global business development.

Here is Burke’s email to NBCU’s staff explaining the changes:

I am writing to let you know that Lauren Zalaznick will be leaving NBCUniversal after 12 successful years working in a variety of leadership roles here.

Those of you who know Lauren well know she is one of those rare executives that combine great creative instincts with a true business orientation. Her contributions to our company have been significant and far-reaching, from cable entertainment to Spanish-language broadcast, from digital initiatives to new marketing campaigns. Lauren also has been an important champion for many of our company-wide initiatives.

Moving forward, most of Lauren’s current group including Lori Conkling, Tony Cardinale, Nick Lehman and Lenore Moritz will report to Cesar Conde. Russell Hampton (Consumer Products) and Paul Yanover (Fandango) will report to Jeff Shell. John Shea and the Integrated Media group will report solely to Linda Yaccarino.

Lauren will remain at the company to transition her current portfolio, and then consult with NBCUniversal on digital media content and technology marketplace trends.

I want to thank Lauren for her years of service. Her drive to innovate, her energy and her intelligence have made our company a better place. She has been an important member of our team and we wish her well in the future.

Steve