As seen on last night’s RAW, Kane defeated The Miz and then asked for Stephanie McMahon to come out. Once she did, Kane told her that it’s time that he does “what’s best for business” and that he’s rendering his services to her to “unleash the monster” as she pleases. Kane then walked up the ramp, took off his mask with his back to the crowd, and handed it to Stephanie as she held an evil grin.
The reason behind Kane going heel and removing his mask is completely due to Kane reprising his role as the evil villain, Jacob Goodnight, in the upcoming WWE Films movie, See No Evil 2. The WWE felt like it would be counterproductive with the marketing of the movie to have Kane keep the mask and continue playing a babyface on TV.
For what it’s worth, backstage sources are saying that Kane may remain unmasked for the remainder of his career.