The CW has added a new description of season 7 on their website:
Now, despite Sam and Dean’s efforts to stop him, Castiel has succeeded in his plan. His power is God-like, and Sam and Dean have no idea how to stop him. But even Castiel doesn’t truly understand the magnitude of what’s inside him — or how dangerous he really is.
Season seven finds Dean and Sam reeling from the loss of their friend. Sam’s violent memories of Hell threaten to overtake him, threatening not just his life, but his brother’s as well. Meanwhile, Dean struggles under the weight of a secret that threatens to tear them apart. And even as the brothers traverse the backroads of America, hunting things that go bump in the night, something is coming for them. They are about to face an enemy more canny and adaptable than any they’ve ever fought. As the landscape around them becomes increasingly treacherous, the tools they’ve come to rely upon will be stripped away. Our heroes, like so many outlaws before them, will find themselves utterly outmatched and outgunned, with no one to rely on but each other.