AT&T has announced sweeping changes to its mobile data plans that will introduce tiered pricing and mark the end of unlimited transfers. Starting on June 7 the carrier will replace its $30 unlimited data package with three new bandwidth-restricted plans called DataPlus, DataPro, and Tethering.

DataPlus will cost $15 a month and offer up to 200MB of data transfer, which AT&T says is enough to send or receive 1,000 emails without attachments, 150 emails with attachments, view 400 sites, post 50 photos to social media sites, and watch 20 minutes of streaming video. DataPro is the new top plan and bumps the bandwidth cap to 2GB of data transfers per month.

The light at the end of this dark and musty tunnel is the addition of tethering, which customers have long begged for. Tethering will cost an extra $20 per month and will be restricted to the DataPro plan. An extra $20 per month seems reasonable for tethering (especially considering the once rumored $55 and $70 fees), but it seems somewhat useless with a 2GB roof.

AT&T notes that most smartphones have Wi-Fi connectivity, and the carrier provides free access to more than 20,000 hotspots in the US. To prevent overages, AT&T will send text messages to warn customers of their usage. One message will be sent at 65%, another at 90%, and then a final note at 100%. Customers who go over will be charged $10 for an additional 1GB.

It's worth noting that folks who currently have unlimited data plans will not be forced into this new model - at least not right away. We assume you'll be able to keep the unlimited plan until your contract expires, at which point you'll likely have to make the switch. We also assume that some "high usage" devices (like the iPad) might be stuck with the $25 DataPro plan, but that's not official.