For once I don't have a strong opinion of my own, so I am seeking your input.
Over the past few years pervasive BI is the big must-have in corporate intelligence systems; that is, making the whole organisation intelligence consumers by giving users performance dashboards and embedding fixed queries into line of business applications. But what of ad-hoc tools? Do workers need tools such as Discoverer or OBIEE Answers in their day-to-day work or do they just drill-down on pre-canned reports in the web browser (or perhaps in a Microsoft shop, Excel)? Of course, there will always be report authors creating the dashboards that will need to use the ad-hoc tools, and others that may be more in to data exploration (and in that case is an ad-hoc tool to limiting).