Tableau vs Spotfire vs QlikView - Which tool is targeted at business users

Three vendors stand out in the Visual Analytics space - Spotfire / QlikView and Tableau. They all solve the same problem - help end users visually analyze data by making users self reliant and reducing dependence on IT to create reports.

The question is - Do these tools meet the criteria for Self Reliance by business users or do they still need IT to create reports (maybe less than the traditional BI tools like SAP, Cognos, Oracle).

I tried to answer this question by going to Amazon and searching for books on these 3 tools and here are the top 4 results for each. I'll let you make your own judgement (check out who these books are written for) -