Heads up, Sprint customers. According to some newly-leaked documents sent over to the folks at BriefMobile, there may be some upcoming policy and plan changes that you'll want to be aware of. First up, it seems that Sprint may be planning to make some big changes concerning its mobile broadband/embedded devices (like tablets). Beginning May 8th, folks activating products like the Overdrive Pro, 3G/4G MiFi, and Galaxy Tab will have three different data plans to choose from: 3GB/month for $44.99, 5GB/month for $59.99, or 10GB/month for $89.99. The good news is that when you pair one of the new tiered plans with one an eligible phone plan, you'll save $10 per month on the embedded device's plan. That means you'll only be paying $34.99 for the 3GB option, $49.99 for 5GB, or $79.99 for 10GB. It's also worth noting that, beginning May 8th, anyone on Sprint's 450 Everything Data plan will be given an extra 300 minutes per month for no extra charge, although it's not clear exactly how long the promo could last.

The other big change is that Sprint has decided to extend its instant rebate promotion that originally kicked off in late March. Previously we'd heard that the promo would end on May 7th, but Sprint has allegedly had a change of heart and extended the offer until June 4th. That means that, when the Nexus S 4G launches on May 8th, buyers won't have to worry about dealing with a mail-in rebate. Hooray!

There are still a few questions we have about Sprint's new embedded device tiered data plans, like whether 4G data will remain unlimited or if it'll now count against your allotted amount of gigabytes, but if the all of the new plans are legit, we should be learning more next weekend. Some folks may be disappointed that Sprint is switching to tiered data for the embedded devices, but the good news is that, after the $10 discount is applied, the prices match those offered by Verizon. So, Sprint users, what do you think of all of these changes?

Via BriefMobile (1), (2)