It is Powered by the Xbox 360 No Batteries, no cables. It would be pretty pointless having a wireless connection if all you had to do to avoid it was spend £5 on a lead that would do the same but be wired. And save you £54-£55 pounds depending on where you purchase it.
Wired networks have been with us since the 1960's and in some ways earlier. It's only been in the last 7 years that wireless has become available. But All you will have to worry about is setting it up with is a router for Media center and Internet (XboxLive) access.