[1] http://www.cnet.com/news/verizon-backs-off-on-plans-to-throt...
[1] http://www.cnet.com/news/verizon-backs-off-on-plans-to-throt...
Neither T-Mobile or Sprint hide the fact that they throttle / rate limit their subscribers for various reasons. So presumably, they are less at risk here.
As for T-Mobile, it's my understanding that they changed their policy to include the possibility of throttling and initially didn't disclose it until it was leaked[2].
Of course, neither of these situations are as customer-hostile as AT&T has been, so maybe the FTC won't go after them. But I wouldn't be surprised if Sprint and T-Mobile make changes to their policies if AT&T loses.
[1] http://bgr.com/2014/05/08/sprint-throttling-unlimited-data-d...
[2]http://bgr.com/2014/08/13/t-mobile-unlimited-data-throttling...
"Unlimited Tablet or Hotspot data plans – choose the amount of 4G LTE data you want to add."