High-end subwoofers? Very common. Wireless subwoofers. They're around. High-end wireless subwoofers? Rare. Rare like leprechauns riding unicorns.
The KEF HTB2SE-W wireless sub combines two well-reviewed products (a KEF subwoofer and their 2.4GHz wireless transmission system) into one very expensive-looking (and costing) package.
Indeed, the sub actually includes dual 10-inch woofers (one is passive to enhance ambient bass) that can be configured to either sit on the floor or stand vertically—kinda like Sony has promoted with the PlayStation brand. But while the subwoofer doesn't need a line run to the receiver, it still needs power, of course.
The HTB2SE-W ships next month for $1200. And on a completely unrelated note, there's gotta be some charity out there that needs $1200 more than you need a fancy wireless subwoofer. [The Audiophiliac]