First, as far as I can tell, there are no wireless speakers. Unless you are counting battery-powered speakers, and I am not, somewhere there is going to be a wire involved. Samsung, Sony, LG, and other major vendors sell at least one model that says it’s ‘wireless’. However, the only wireless part is between the main unit and the rear speaker receiver.
Unless you really want the full surround sound effect, I would consider looking into Sound Bars. They have become popular because of their simplicity of setup and relatively low-cost. Usually, it just takes a power cable and an interface cable between the device and your TV. All major brands are wall mountable and generally include the bracket. I recommend the models with the wireless subwoofer. The subwoofer on those models just needs to access to an A/C outlet and it finds the base unit all by itself.
If you really want full surround sound, then consider how you can run your wires. If you live in an apartment and cannot run wire through the walls or simply don’t want to tear up your walls, then models that offer the wireless rear speaker option are perfect. These models have the rear speakers wired to a receiver, which is plugged into an A/C outlet, to wirelessly pick up the rear sound channels. Phil Lozen from Electronicshouse.com has a great article that goes into depth on, among other things, wiring options.
If you have an existing system and want to take it wireless, there are several companies who manufacture adapters which convert wired speakers to wireless. A quick Amazon search and I found companies like Nyrius ARIES, Soundcase, Rocketfish who sell these adapters.
Wireless HD video is a relatively new technology but quickly growing. Nyrius ARIES makes several models that are infrared transmitters. Infrared is better because, unlike radio frequency receivers, it is less likely to get interference from other devices. These devices, unlike AppleTV or Roku allow you to transmit any HD source, not just the device’s content.
In short, if you want that clean look to your wall-mounted TV (provided you have a power jack behind the TV) you now have the tools to do it.