Ben Dooley explains why they're not going to made into English any time soon:
There are a number of features of Japan's language and culture that make a cell phone novel more palatable than it would be in English. First, Japanese grammar is much better suited than English to the kind of short sentences writing on a cell phone encourages. As a high-context language, a complete sentence in Japanese can consist of just a single, lonely verb.
Japanese speakers and writers frequently and freely omit subjects and objects from their sentences, expecting the reader to figure out what's going on. Go figure. The use of Chinese characters also serves to compact sentences. Since you don't have to actually spell out entire words, as in English, but can represent them with an ideogram, you can say a lot more in a much smaller space.
Secondly, and perhaps just as important, cell phone novels tap into long traditions of Japanese prose and poetry. First, even a cursory examination of a cell phone novel will show a visual connection to the poetic traditions of haiku and tanka. The connection doesn't end there, at its best the writing itself has an economy and - I'll regret saying this - poetry that taps into the same tradition. The medium - you try typing a novel on the keypad of a cell phone - forces the writers to make every word count, and (in Japanese at least) it shows.