Amidst the flurry of Apple tablet rumors, a new iPhone rumor has managed to float to the surface: Apple will be breaking from its traditional June/July iPhone update window in favor of a May roll out this year, according to Challenges.

Along with an earlier launch time, the fourth generation window will allegedly sport a 5 megapixel camera and LED flash, and possibly an RFID chip as well.

Apple hasn't offered up any indications that it plans to update its iPhone line up earlier than it has in the past, but a May rollout for the fourth generation model would potentially make the device available ahead of the company's annual World Wide Developer Conference. Apple is rumored to be planning its annual conference for some time in June, although the company hasn't yet officially announced the conference dates.

If Apple does release the 4G iPhone model early, it could also be seen as a move to help prevent Android-based smartphones, along with Google's Nexus One, from eating into its marketshare.

Apple has a history of introducing new iPhone models in the June/July window, and hasn't dropped any hints that it might launch the fourth generation iPhone earlier. For now, treat this rumor as just that: A rumor.