Eager to reach younger and more affluent U.S. Hispanics, advertisers, publishers and cable television networks are discovering it is best to speak to them in their own language--English. Spanish may be the dominant language of Latinos, the fastest-growing ethnic group in the country. However, for bilingual, better-educated young Hispanics, English increasingly is the media language of choice. In response, a new crop of English-language television networks, radio stations and magazines have emerged to offer fresh choices to "acculturated" Latinos, those who maintain their Latin roots but identify closely with the American mainstream. "Marketers have long been frustrated that there aren't...