AT&T is doing something I've never understood why people let companies get away with. They're charging an extra $20/month for the tethering plan. Tethering is something that the iPhone does by itself it doesn't require any expense at all for AT&T. I could understand their tactic if they were still offering unlimited data plans because you would expect someone who uses their cell phone as a modem for their computer to use a lot more data. That's not what they're doing though, they're selling 2gb of data for $25/month. What's AT&T's excuse exactly? That for tethering users they're worried that people will actually use the data that they're paying for?
This is one of the reasons companies like to offer "unlimited" one-size-fits-all plans. The plan is unlimited but really it's more like 5gb, and almost nobody actually uses that much, and it's not ok to tether because then you'll be using more than they planned for, and nobody complains because you think of it as a plan that's "unlimited" but only up to the point that a cell phone would be expected to use. (Essentially Comcast and their ilk do the same, my "home" internet is "unlimited" but not exactly and only in the amount and reliability that a home user would expect, and in some ways that's ok.) But when these companies decide to change the plan to "you get 2gb/month" then I damn well expect that my 2gb should be given to me in whatever way I want it.
There's another little thing in this press release that I'm a fan of. For the 200mb plan (really, 200mb, really?): "If customers exceed 200 MB in a monthly billing cycle, they will receive an additional 200 MB of data usage for $15 for use in the cycle." And for the 2gb plan, "Should a customer exceed 2 GB during a billing cycle, they will receive an additional 1 GB of data for $10 for use in the cycle." Hooray everybody, it's the old Blockbuster late fee model! Use 2.001gb of data in a month pay for 4! Hooray!