According to a report in the New York Times, the CEO of Softbank, Masayoshi Son, indicated in a phone interview that more aggressive price cuts will be coming soon to Sprint. Here's a quote with the details,

In a phone interview, Masayoshi Son, SoftBank’s chief executive, hinted that further price cuts could be in the works as the company invests to upgrade Sprint, America’s No. 3 wireless carrier.

“We will be aggressive in technology, price packages, services on every front,” Mr. Son said from California on Wednesday. “At the same time, we will improve the network to be the world’s best,” he said.

SoftBank, the Tokyo-based Internet and mobile communications giant, has a reputation in Japan for undercutting rivals on price to gain market share. Mr. Son has been behind a sharp decline in prices for broadband and cellphone services in Japan.

Expectations are high that Mr. Son will bring that strategy to Sprint, which has struggled with subscriber defections for years and that Mr. Son will inject healthy dose of competition to America’s mobile industry.
If true, it could be a real shakeup in the U.S. carrier industry. Mr. Son is credited with sparking an aggressive price war by undercutting the competition. If he can do the same thing with Sprint in the U.S., we might finally see some competitive pricing with the other big U.S. carriers.

Source: NYT