I found need for this same solution. I am using it in one of my prototype applications for home-control.
The problem you cite is only the first of a couple of problems you'll run into. I believe i have full the solution now working for both iPad/iPhone (Universal app).
You can read my post here: problem and solution description with sample code at my blog
In summary, you'll run into the following issues (most for iPad imple., some for iPhone imple. when building Universal app.):
- The template code in appDelegate sets up delegate incorrectly for the new shape (it really no-longer understands what type of controller is present for the detail view
- UISplitViewController delegate calls are not propagated thru the UITabbarController to the tabs correctly
- You will need to decide how/when to notify the tab(s) of the current detail selection
- When building as Universal App some of the notification now need to happen in prepareForSegue: methods (as some of the other notifications don't happen on the iPhone platform.)
(All of this is shown at my blog post)