Wired reports that U.S. carriers are hesitant to adopt new dual-mode phones that work on both cellular and Wi-Fi networks. Gee I wonder why?

Developers of software for so-called dual-mode phones, which can switch automatically between traditional cellular and wireless broadband networks for voice calls, are aggressively pushing the technology to carriers. So far, no U.S. carrier has announced plans to deploy a dual-mode Wi-Fi phone.

However, industry analysts say research indicates that there would be sizeable demand from cell-phone customers should such devices hit the market. A recent report by one firm, ABI Research, predicted that by the end of this decade there will be more than 100 million handsets in the world that can connect to either a cellular network or a Wi-Fi network for voice calls.

“Cost is a real factor in all of this. If you’re in a Wi-Fi setting on a cell phone, it’s fast and it’s cheap,” said Neil Strother, senior analyst at In-Stat, who doesn’t expect the technology to gain a large following for another year or two. Among early adopters, however, Strother expects dual-mode phones will sell well. According to a survey of cell-phone users released in April, In-Stat found that more than 4 in 10 respondents were very or extremely interested in buying a wireless phone with built-in Wi-Fi for voice and data.