Well, normally I have great admiration for the folks at ANN, but they really kind of cocked up this piece of news and still managed to cock it up after being corrected by Brian Ruh.
Co-creator of Revolutionary Girl Utena, Saito Chiho (who drew the TV manga and movie manga versions of the Utena story) is launching a new manga in Flowers magazine called Torikaebaya.
Based on the picture that ANN shows, it's not that she's doing a new manga with a similar story to the Heian classic, Torikaebaya Monogatari, but that she's doing a manga adaptation of this story (which is hideously called "The Changelings" in English.)
Some of you already know this story - The Yamayurikai perform it as a play in the 4th season of Maria-sama ga Miteru/Maria Watches Over Us.
The story is not "transexual" as ANN says, it is a very old 11th century story about brother and sister nobles in the Heian court that do better in gender roles assigned to the opposite sex. The Princess makes a good Prince and her brother amkes a better Princess. (Although they are really nobles of the court, they are referred to as Prince and Princess.)
Here's the Wiki article about the story: http://en.wikipedia.org/wiki/Torikaebaya_Monogatari
I imagine that Himegimi will make a dashing male courtier. So, something to look for next month when Flowers debuts the story.