3:25 PM -- So, I checked with Sprint Corp. (NYSE: S), and unlimited data plans aren't going anywhere, at least for the time being.

This is what a spokesman for the operator told me Monday: "Unlimited data is a key differentiator and we have not announced any plans to stop offering them."

My read on that statement is that Sprint will keep unlimited for now, but is leaving its options open for the future. In fact, CEO Dan Hesse has always made it clear that unlimited could change in the future.

So that's that, for now.

There is another interesting question in this whole SoftBank Mobile Corp. investment, though. (See Softbank to Pay $20B for 70% Sprint Stake and Sprint: SoftBank Will Not Change Network Vision.)

What happens to Sprint's WiMax partner, Clearwire LLC (Nasdaq: CLWR), in this majority acquisition? The market is already speculating that Clearwire could be next, with the company's stock up over 16 percent to $2.70 on Monday.

But Sprint could have other options, suggests Heavy Reading analyst Berge Ayvazian.

"If I was Dan Hesse, I would rather take the Softbank money and try to break up the MetroPCS merger with T-Mobile USA rather than invest more in Clearwire," Ayvazian tells me. "But I would turn back to secure Clearwire’s TD-LTE network if this effort was not successful."

Long Term Evolution Time Division Duplex (LTE TDD) -- otherwise known as TD-LTE -- could potentially be interesting as a roaming option for SoftBank in the future. The Japanese operator launched its LTE TDD service domestically in February 2012.(See Just What Is LTE TDD Anyway?)— Dan Jones, Site Editor, Light Reading Mobile