I certainly think the expanding backlist of trade published writers re-releasing as e-books will be big over the next few years, but I’m not convinced it’s going to be so big that new writers won’t be found. The more lasting backlist novels have remained in print, while many of those that have gone out of print did so because they’re far less relevant than they were when first released.
Whole genres that were popular a couple of decades ago don’t really have much relevance to people today. Cold War thrillers, for example, or post-WWIII nuclear survivalist action novels; the good ones are still around, but the majority probably deserved to vanish into the depths of $0.99 used book sales on ebay. SF stories set in the far future may still be relevant, but those set in the near future written a couple of decades back, not so much; I remember one of Clarke’s novels where he wrote about people entering competitions to find information on a global information network… it was probably pretty cool in the 80s, but today it’s rather quaint and most people would think ‘why don’t they use Google?’