With AirPlay mirroring, you can also stream everything from a Mac that meets certain requirements. So if you have a new MacBook and TV, you can watch stuff on your big TV that the providers don't want to let you see unless you're at a much smaller computer or pay for something like Hulu Plus. So if you don't own something like an Xbox with ESPN3 but you have a MacBook, with AirPlay you just brought all that stuff to your TV. Same with the free Hulu from the website and tons of YouTube and other video options.
Home Sharing quite simply is iTunes on your TV. The reason a lot of us bought TV devices.
Can you explain what you're talking about?
If my wife is watching her TV shows on ABC.com, she can mirror it to the TV? Is that what you're talking about?