From
PC Magazine
HTC's upgrade of the HTC Sensation on Wednesday to Android 4.0 will be bittersweet, as a T-Mobile representative said that the company will begin enforcing its $14.99 per month wireless hotspot plan.
That probably means that the carrier's policy of letting some customers use the feature for free will end, making a Wi-Fi hotspot subscription mandatory for those who want the "Ice Cream Sandwich"/Android 4.0 upgrade, and wish to keep using the phone as a wireless hotspot.
Looks like they got the bugs worked out so they can actually start billing people for it.
Fifteen bucks a month is a good deal if you need it, but of course not a good deal if you were getting it for free.