Microsoft is airing a new TV ad for Windows 8 tablets targeting their main competition, the Apple iPad. The spot points out that the iPad is missing equivalents to Windows 8 features like Live Tiles and true multitasking, and that at $449, a 64GB ASUS VivoTab Smart tablet is far cheaper than a comparable 64GB iPad, which is $699. Narrating everything is a Siri-like voice trying to defend Apple.