You know that a given technology field is "going mainstream" when it starts to get moderately intelligent coverage from the non-technology mainstream press. So when I saw today an article titled "Reaping Results: Data-Mining Goes Mainstream" in the "Your Money" section of The New York Times, I had to give it a read.
You can find it online here (free registration is required): http://www.nytimes.com/2007/05/20/business/yourmoney/20compute.html
It's not anything earthshaking or groundbreaking, but I think it does a decent job of presenting a complex BI technology in a manner that non-technical people can appreciate and understand. If you're in a position where you need to present data mining and BI to someone who "just doesn't get it" (especially since they always have the biggest budgets!) this might be worth sharing with them.