I believe that it's against code because of the risk of fire. Definitely DO NOT run the power cable through the wall. If it causes a fire, you'll not only lose your home, but you'll get zip from the insurance company.
You can just plug the TV into a surge protector on the floor and use one of those plastic covers over it (
example). It won't be too noticeable if you paint it the same color as the walls. That's what I'm planning to do since I have dirty power at my house and need my TV plugged into an AVR.
Actually, I must say thank you for posting this thread, because it caused me to do some good research. I was going to post about a surge-protected outlet, but I can't use one of those at my house. I have dirty power and need my TV plugged into a surge protector with AVR. However, I found
this avsforum thread that mentioned the
PowerBridge. It basically runs up-to-code wiring through the wall between an outlet behind the TV and one near the floor. It's also recessed and can be used for other AV cables. You don't actually connect to any electrical wiring, so an electrician isn't needed. You have to plug an extension between your surge protector, UPS, AVR, etc. and the outlet near the floor to provide it with power. It seems really slick and well-praised on avsforum.
The Total Solution costs
$54, which includes everything except the AV cables, but it does include a hole for the AV cables. If you just need the outlet, then the Single Solution is
$48. I'm not sure how much shipping costs or if these are the lowest prices, so you'll probably want to do some searching before buying.
My wall mount's on its way, so I guess I'll be ordering the PowerBridge in the near future as well.
I just noticed that PurdueRy posted a very simlar product to the PowerBridge. PowerBridge includes everything you need, has more reviews, and is about the same price, so I think I'll go with that one.