THE seeds were sown, and the initial fruit reaped, by enterprising satellite television broadcasters down South. First it was Tamil. The result: roaring success after de rigueur teething problems. Then came Malayalam, Telugu and Kannada. Bull's eye once again. The little plant in the backyard is now a big tree and its branches are spreading in new directions. Gujarati is on the way. And Punjabi, Marathi and Bengali could well be next. Indeed, the language-niche channels, poised on the threshold of a major explosion, seems to be the way to go.