When you purchase the iPhone SDK it enables you to add any app you make to your physical iPhone. Does that mean without jailbreaking you can download peoples projects that have been rejected by tye app store and install it using your iPhone SDK?
If they chose to give you all the source code so as you could compile it with your signing profile, yes. Otherwise, no. Apple certainly don't provide this.
Has anyone tried shipping just the linked object code and app bundle without the last codesign step (which Xcode documents in the middle Build pane), and having the recipient developer do that last step on the command line?