The spotlight may land on other Marvel mutants, but Rogue is actually the X-Men's most committed member. The X-Men's own Southern Belle actually made her debut as a supervillain, and a member of Mystique's Brotherhood of Evil Mutants. Traumatized by the development of her own powers, she'd fled from home, and found a surrogate mother in the mutant terrorist.
But Rogue's powers were completely out of control, and she was left deeply scarred after an encounter with Captain Marvel, Carol Danvers, who at the time went under the codename "Ms. Marvel." Rogue unwittingly absorbed Ms. Marvel's powers on a semi-permanent basis, while Carol's mind seemed to have become a part of Rogue's own psyche. Desperate, she fled to Charles Xavier, who offered to teach her to control her abilities if she earned it. It was an unlikely beginning for the woman who is still proving to be the X-Men's most committed member.
It took the X-Men some time to learn to trust Rogue, but she proved herself time and again, even earning the grudging respect of Wolverine (who had every reason to hate her, given his own history with Carol Danvers). Finally, in Uncanny X-Men #247 Rogue was blasted into the Siege Perilous, a mystical portal that would grant anyone their heart's desire. Over the following months, other members of the X-Men stepped into the Siege Perilous as well, and were transformed. Colossus forgot his past and lived a happy life as an artist, Psylocke became a warrior as she had wished, Dazzler regained her musical career. But unique among all the X-Men, Rogue emerged from the Siege Perilous in the X-Men's outback headquarters. It was a subtle way of revealing she already had her dream; a life of redemption where she used her powers for good and not for evil. Unfortunately, of course, it was just bad luck that the X-Men's base had since been claimed by a bunch of mutant-hunters known as the Reavers.
Rogue has had one of the most fascinating and consistent character arcs in X-Men comics. Over the years, she has learned the truth of her mutant powers, and has gained mastery of her abilities. But, significantly, she's one of the few X-Men to truly seem committed to passing on the lessons she has learned to the next generation of mutants. When the X-Men lived on the island nation of Utopia, Rogue took on a role of student counselor, helping various young mutants deal with the psychological traumas some of their powers caused. She was the X-Man who bonded most closely to Hope Summers, viewing her as a person rather than just the Mutant Messiah. Rogue's commitment to Xavier's Dream was even demonstrated by her decision to join the Avengers' so-called "Unity Squad." Created after Charles Xavier's death, this group consisted of humans and mutants working together, and was intended to serve as a visual demonstration of the fact coexistence was possible. It didn't take long for Rogue to become field leader, chosen by Captain America in part because of her ability to put the wounds of the past behind her.
It's important to remember this personal history in the light of the mutants' new status quo. The X-Men relaunch has seen the entire mutant race gather on the living island of Krakoa, acknowledging Charles Xavier's Dream is dead, and replacing it with one that's far more isolationist and... morally questionable. But even if most of the mutants seem to be going long with their leader, Rogue is voicing that she's ever so slightly uncomfortable with the new direction, openly questioning some aspects of Krakoa's way of life. For example, she and Gambit have decided to reject the Krakoan law to "make more mutants," with Rogue not willing to allow any law to dictate what she does with her own body.
It will be interesting to see whether the most committed of the X-Men is ultimately content to remain on the island, or whether Rogue begins to question it. For now, the seeds have been planted to show Rogue may prove she's Xavier's greatest student... by adhering to his belief, more than the man who has abandoned them.