Sprint’s widely promoted unlimited plans are beginning to dry up and blow away.

Last month it was unlimited hotspot plans that got capped. Now it’s any 4G broadband device that isn’t a phone.

According to Sprint: “If you have a mobile broadband device such as a tablet, netbook, notebook, USB card, connection card or Mobile Hotspot device, effective beginning with your next bill following notification, your on-network monthly data allowance will no longer include unlimited 4G.”

Starting next month (November, 2011):

– If a users current data plan is 3GB of 3G data, and unlimited 4G data, they will be capped at 3GB of combined 3G/4G data, and 100MB of roaming data.

– If a users current data plan is 5GB of 3G data, and unlimited 4G data, they will be capped at 5GB of combined 3G/4G data, and 300MB of roaming data.

– If a users current data plan is 10GB of 3G data, and unlimited 4G data, they will be capped at 10GB of combined 3G/4G data, and 300MB of roaming data.

The cost for going over the cap is $.05/MB on network, $.25/MB if roaming. The new caps will be applied to both new and existing users.

Sprint also says on their site that “if your phone plan contains unlimited data, you will continue to enjoy unlimited data usage on your phone while on the Sprint network.”

However, some analysts are predicting that Sprint’s unlimited data on smartphones will also come to an end sometime soon.