We'll just have to see, I guess. Still, I think the future growth of AdSense will be determined by product extensions and increased services to advertisers, not by making it easier for publishers to override Google's algorithms.
Remember, too, that Google is a company that was built around scalable solutions (a.k.a. automation). When AdSense was introduced, the pitch was fairly simple: Put our code on your pages, and we'll pay you money. In other words, AdSense was never intended to be a product for publishers who wanted full control over their ads; it was designed for publishers who wanted to let a third party (Google) worry about the ads while they (the publishers) focused on their sites.