Have you already hammered out adjustments so your app will run on the iPhone 5? Has it been submitted to the App Store? Are you waiting on it to be accepted? I have updated our app to run on the iPhone 5 but have not tested on actual hardware yet so I want to wait for that to happen before I submit.
It did get me thinking about the iPad mini. First off if it actually exists what resolution will it be? Should it be double the size of the iPhone 5? That makes some sense to me as they are looking at videos and deeming the wide screen presentation is the way to go. Will it be same resolution as the iPad 3 in a smaller package? Makes it easier on tablet development and really that resolution is fine for a 7-8" screen. Heck there are much smaller Android phones running higher resolutions than the iPad.
Let's say they go with a new resolution. You get to update your app yet again. The main app I have is universal - same code runs on iPhone / iTouch and iPad. The update to iPhone 5 was pretty simple as I try to avoid hard coding. Since I also wrote the Android version I already need to think resolution agnostic. I tend to not think in absolutes coming from a PC background. Hopefully my code will port quickly.
I have special checks in the code now for the iPad as the status bar is the same height in portrait and landscape mode on the iPad where as it changes height on the iPhone based on orientation. I really wish you could query controls for their current / minimum / preferred dimensions. Maybe in a future release of iOS.
At this point I think I am better off waiting to submit anything to the Apple Store until the iPad Mini release is confirmed for October or nothing happens. I can submit one app and catch all the new resolutions. I will have to decide if just testing via the simulator is enough. Since I know my app runs fine, as far as speed is concerned, on actual devices how far can I trust the simulator? It gets tough for a small company to buy a lot of testing hardware. I know I have already put a lot of faith in the various Android emulators and so far have not run into issues and I can see from our Google Analytic data that our users have a wide range of Android devices and we have yet to have a layout related issue reported to us.
Apple recommends testing on actual hardware always. I really do see their point but at some juncture you have to punt. I don't have an iPad 1, 2 and 3 along with iTouch Rev 1 - 4 and iPhone up to 5. I have already given up testing on each type. As a small shop, I am the only mobile developer, we just don't have a bunch of techies upgrading their phones in lock step with Apple. I don't know anyone with an iPhone 5 at this time. Heck my personal phone is only 2.2. I do have a Jelly Bean tablet.