In his testimony, Jason Devitt talked about many types of applications that don't come to market today, but he ran out of time before covering the most important one: applications that don't look very lucrative, and therefore the carriers have no interest. From his written testimony:

Inevitably, carriers are not interested in devoting time and resources to devices or applications that they don't believe will be of interest to the majority of their tens of millions of customers. . . Forcing entrepreneurs to seek permission to innovate in mobile services is killing powerful new ideas before you ever get to hear about them. Imagine the founder of Amazon having to persuade Sprint in 1995 that he could do a better job selling books online than Barnes & Noble. Imagine the founder of eBay trying to explain to a mid-level manager at Verizon that trading stamps, coins, and dolls online would be a good way to make money. Picture the founders of Google in 1999 persuading AT&T to let them launch another search engine. This is the daily reality for those who develop mobile applications.

There's another related class of applications Devitt doesn't mention: applications that will probably never make any money. In addition to the Amazons, eBays, and Googles, of wireless technology which entrepreneurs will create, we want the cool little toy applications like Friend Wheel, the personal Web sites, and the ability for nonprofit organizations to organize using mobile technology. All of these are unlikely to ever grow into a lucrative income stream for mobile carriers, but thrive on the Internet, where no carrier has to give permission or extract a burdensome toll.