And I bet they do work fine more often than not. Of course YMMV.It's really not any different than what many have already done using wireless bridges, just incorporates the wirless into the box itself instead of having to add a bridge.
UVerse routers are Wireless-G. If you get their wireless receiver they also give you a Wireless-N access point to plug into the router. This does give you the option of placing the access point at a drop closer to the TV.