Following your post in the Bluray thread (wireless surround sound system wanted), there's only a handful I know of - and I haven't used any of them, so can't give them any sort of recommendation.
First, the obvious.
You want speakers that output sound, without wires. It's technically impossible.
With a traditional surround sound system, there's wires with minimal voltage/current going to each speaker. In a wireless system, you need to power the receiver (whatever technology that be).
So if you want wireless audio transfer, you need some means of powering the speakers. Power cables are generally thicker than audio cables, and I'm guessing you don't want to be swapping batteries infinately.
Now the less obvious.
There's several wireless technologies in use for the job at the moment. First being Bluetooth (because it's a "fad" IMO, so it was "cool" to use Bluetooth for surround sound). Bluetooth has a transfer throuhput (from a practicality viewpoint) of 433kbps. Dolby Digital requires 400kbps, and full DTS requires 448kbps for a full 5.1 surround stream. That's Bluetooth out the window then (don't buy any surround sound system using it, you won't get surround sound out of it!).
As for the others, there's naturally things like IR, but again, I'd rule these out for reasons of bandwidth (unless you opted for an MIR or FIR setup - both of which take more power & will cost more to run) & physical line of sight limitations.
Then there's Wifi-ish ranges, 2.4Ghz specifically is what most manufacturers seem to use. Obviously you're already aware of possible interference by other Wifi networks in the area sharing the same channel.
Another thing not often considered, is the digial amplification of the received sound by the 'satellite' speakers. This is done by Class-D amplification in 99% of cases, which can be quite a lossy way to amplify the source (dependant on hardware).
Given all the above considerations, especially the fact that you will still need a power cable to the speakers, are you really still wanting a wireless surround sound setup? Especially when a wired system will generally be cheaper, and better quality than it's wireless brethren.
If you are, I can point you to a few manufacturers etc. I just didn't want to derail the other thread with all this opinion.
