I'm not sure any effective design/communciation piece could survive without well written copy. Ads, long copy or not, require just as much attention to aesthetics as object/photographic-based concepts. I think a well trained typographer can make 10 words look simple, and 200 hundred a typographic master piece. People read, when they're interested. Text can be an amazing visual in itself. Copy my be well written, but initially, it's how it's presented that draws interest. Typography will enhance any piece. "Will copywriters end up as bandaged mummies in museums?", maybe.
If so, they'll undoubtedly be right next to the type masters.