Two recent reports are weighing in on the big question facing the wireless industry: will rising data revenues make up for slower subscriber growth in the U.S.?

Facts: The U.S. penetration rates reached 84 percent at the end of 2007. Last year, annual U.S. data revenues totaled $23.2 billion, or 17 percent of overall revenues totaling $139 billion, according to CTIA.

Here’s the two sides of the debate:

Yes: If you can use other countries as a model, the answer is yes. In countries, such as Japan and Korea, premium content has seen dramatic growth with some operators recording data revenues exceeding 30 percent. The main drivers are premium content, such as full-track music downloads, mobile games, but increasingly also things like mobile video, according to MultiMedia Intelligence. Separately, some U.S. operators believe that revenues may increase from other sources as wireless chipsets are put in all sorts of devices going forward, including cars and home electronics.

No: A transition from subscriber-led growth to data-led growth is coming, but it won’t happen smoothly, according to Sanford C. Bernstein & Co. The study found that subscriber growth is decelerating sharply in the U.S., with the industry adding 23 percent fewer new subscribers in the first quarter compared to a year ago. Today, subscriber growth—not data ARPU growth—still accounts for nearly 90 percent of wireless revenue growth at Verizon Wireless (NYSE: VZ) and AT&T (NYSE: T). By 2010, they expect the market to reach full penetration at 89 percent. “We are entering a share game rather than a growth game....We believe that wireless sub growth is likely to decelerate too quickly to be easily offset by rising ARPU (average revenue per user). We expect a “U-shaped” growth trajectory, where overall revenue and EBITDA growth can be expected to slow significantly before re-accelerating.”