Apple further solidified its hold on the portable music industry in March as the iPod Shuffle gained popularity among consumers according to new data released Wednesday. Research firm NPD also reported that the much-delayed iTunes phone from Motorola was not being held up because Apple was against sharing revenue with carriers.

iPod Shuffle's share of the market grew 15 percentage points to sit at 58 percent in March. Meanwhile, Apple's share of the hard-drive based market remained at about 90 percent as in previous months, and the iTunes Music Store had a 70 percent share of all digital music sales.

Steven Milunovich of Merrill Lynch said that there was still room for the company to grow internationally, such as in Japan where 60 percent of music players are non-Apple based, and called the numbers "stunning."

Apple management also appears open to a revenue-sharing model according to the company's CFO Peter Oppenheimer, despite press reports to the contrary. Oppenheimer says that Apple sees music-capable phones as more of a compliment to the iPod than a replacement.

Merrill Lynch's Milunovich also believes that video capability and wireless connectivity will make it to iPods before the holiday season. Also, an ad campaign to highlight Apple's computer offerings may be in the works.