Each of our sub panels resides in a separate user control that we dynamically load. The code that that loads these sub panels is very simple, so it should not take more than 2 hours to convert the first DetailView to use a tabbed view, assuming that Telerik already has this ability. Then, it would probably take another hour to duplicate this code in all of the DetailViews.
If you get stuck, just give our support staff a call and I'm sure there will be able to point you in the right directly.