Sprint will start limiting mobile hotspot use, when a phone is turned into a Wi-Fi gateway, to 5 GB for both current and new subscribers starting 2 October 2011. Additional gigabytes cost $50 each, billed by the megabyte. Sprint is the last U.S. carrier to offer true unlimited 3G service, which remains available for on-phone data usage — for now! follow link
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Sprint Imposes Mobile Hotspot Data Limit
Didn't Sprint announce that they would not be capping data? That was a bogus report I believe.
As noted in the brief above (and linked article), Sprint is retaining unlimited on-phone data. It is also apparently not limiting higher-priced enterprise accounts. However, the company has confirmed the mobile hotspot cap.