The CTIA is tapping the Entertainment Software Rating Board for a new push into classifying mobile apps, with a system set to be unveiled on November 29th. We don't have much information yet, and it's worth keeping in mind that the ESRB has been rating apps for a while, but as the CTIA represents the wireless industry its involvement could point to wider adoption.
While anyone could have submitted apps for an ESRB rating before, so far mobile app stores have mostly regulated themselves. For example, the page for Grand Theft Auto: Chinatown Wars in the App Store has a list of content such as "Frequent/Intense Cartoon or Fantasy Violence" and an overall rating (tied to parental controls) that says "You must be at least 17 years old to download this application." The ESRB thought much the same about the DS and PSP versions, breaking down the content in simpler terms and giving a rating of Mature (17+). The board does give more detailed rundowns of game content on its website, though, and it's possible that they could be integrated into digital ratings.
Currently, publishers like EA and Activision submit their games to the board because stores won't carry them if they don't, but the thousands of independent app developers out there don't have that motivation... unless Apple, Google and other storekeepers are willing to make new ratings a part of their approval processes, of course. What might be in it for them? The burden of rating each app individually might be lifted off their shoulders, and their efforts to regulate content could gain some legitimacy. We'll have to wait until next week to see what the ESRB has up its sleeve.