If rumors are true, and Apple is delaying the release of iOS 7 for the iPad, we're in for a fun couple of weeks..
1. Plenty of apps are universal with the same binary running on both the iPhone and the iPad.
2. Plenty of developers are thinking on releasing apps that are compatible with iOS7 only.
So if Apple updates only the iPhone to iOS 7 in September while releasing the iPhone 5s or whatever the next iPhone may be called, and leaves the iPad running iOS6, this will mean the iPad can't run these newest update until it too is updatd s to the new iOS sometime on October.
For developers planning all new apps with syncing that isn't backwards compatible, this is an issue cause syncing becomes a mess. For users planning on buying the new apps, this is an issue cause they can't install them on their iPads. For users currently owning the app, not so much. Their iPhone will update the app, and the iPad will keep on running the older version until it too gets an update and becomes eligible for the new binaries.
Either way, I hope Apple gets their act together, and releases the entire package in one go, somewhere in September.