Rachel Nichols, an ESPN fixture covering nearly every sport since 2004, is leaving the network for CNN/Turner. CNN announced the move late this afternoon.

ESPN employees privately expressed shock at her departure, which comes on the heels of losing Sportscenter host Cindy Brunson in October, and Erin Andrews and Michelle Beadle last summer. One could argue that after Hannah Storm, Nichols was ESPN’s most prominent female voice (host or reporter). Who takes that spot now? Suzy Kolber? Sage Steele? Chris McKendry? Lisa Salters?

Nichols starts at CNN Jan. 28th, and she’ll be anchoring the network’s Super Bowl coverage from New Orleans with Ernie Johnson. Expect to see her doing plenty of NBA work, as well as MLB in the postseason.

A source said Nichols had two offers from major networks, and one from an all-sports network, and ESPN’s offer was “tremendous.” It didn’t, however, include hosting duties. The move has been in the works since about October, the source said.

We’ll drop in this “big names to leave ESPN” list from 2011; but ESPN will quickly counter that it retained 97 percent of its talent last year.