For the last two years, unlimited data plans have given app-hungry smartphone users an all-you-can-eat buffet. But will customers react to AT&T’s new, limited menu by simply eating less?

Some software developers fear they will, and if that happens, the caps on data use that AT&T has imposed could also make consumers lose their appetite for the latest innovations. Some developers worry that customers will be reluctant to download and use the most bandwidth-intensive apps and that developers will cut back on innovative new features that would push customers over the new limits.

“What created this lively app world we are in was the iPhone on one hand, and unlimited data plans on the other,” said Noam Bardin, chief executive of Waze, which offers turn-by-turn driving directions. “If people start thinking about how big a file is, or how fast an application is refreshing, that will be a huge inhibitor.”

New features on phones encourage more data use and vice versa. The next version of the iPhone, set to debut on Monday at Apple’s Worldwide Developers Conference in San Francisco, will include a second, front-facing video camera, according to leaked reports. That could conceivably allow developers like Skype to offer face-to-face video calls from phones  a service that is much more data-intensive.