For anyone waiting for a new iPhone, my guess is you've got a long wait. Apple's industry leading device is selling well enough, even in India, that it doesn't have to worry about slowing sales other than what's seasonally adjusted.
However, if you're looking for possible signs that new iPhones are coming other than waiting until fall, there could only be one. And it's not from rumor sites either. When every authorized iPhone resellers begin to discount them, that's a pretty good indication that Apple is trying to drum up last minute sales before new models arrive.
For instance, we can see anywhere from $50 to $100 in discount on the iPhone 5. This happened the last couple of years.
And it's probably anywhere from six to eight weeks ago when Apple starts doing that. For those who are hoping that Apple will release new models in June, Apple will have to start discounting current models right around the beginning of April.
Another time frame that rumor sites have indicated is August. So, right around Apple's World Wide Developer Conference in June, that'll be when Apple and partners starts discounting.
My money is still late September. Even with Samsung releasing the Galaxy S 4, there just isn't enough competition from competing flagship devices for Apple to worry about shortening the window of annual iPhone refresh. Don't get me wrong, the newest Galaxy is very awesome and should get Android fans fired up. For anyone else, choosing between an iPhone versus a S 3 or S 4 is not that big of a difference.
Personally, I had hoped that the Galaxy S 4 would have blown the lid of the mobile market and force Apple's hands. From all indications, that probably won't happen.