I think I’m missing some controls in the tool window in Xcode 4.3.2.
I created a new iOS 5 project, and my list of controls looks like this:

I noticed that I got more controls when I opened a sample project downloaded from the Apple dev site.
Then I tried to open my own project, which started out showing a code file. Then I got a huge list. But as soon as I view the storyboard, or a Xib file it reverts back to the shorter list.
In the huge list of controls, some of them doesn’t look iOS-ish. I suspect that it loads the whole lot Xcode has to offer across project types (both iOS, Mac). Looks like this:

Do I need to manually load some frameworks, or similar into my project in order to get more controls?
The first screenshot shows the CocoaTouch controls, the second one shows standard Cocoa Controls. Not all of the latter ones are available on iOS/CocoaTouch. You can change the filter with the drop-down menu directly above the list (“Objects” in the first screenshot, “Object Library” in the second one)