It's almost as if there is no way out. Those still grandfathered with unlimited data plans are throttled if they are among the top consumers of data in a region, while others are on tiered data plans that limit how often video streaming services like Netflix can be used. The aforementioned update allows users of the Apple iPhone and Apple iPad to toggle the device's 3G/4G connectivity on and off basically giving the user a chance to view Netflix only through Wi-Fi. While that could save you a ton of data, the trade-off is that you will have to find a Wi-Fi signal before you view a movie or T.V. show.
source: GIGaom via SlashGear