According to CNET, multiple sources have indicated Jobs intended the iPhone 5 to be the major overhaul to the platform many people expected this time around, including a larger screen and LTE support.
It will, reportedly, be redesigned on the outside and be introduced at Apple's WWDC (Worldwide Developer Conference) next year.
The idea of Apple introducing a new iPhone so soon seems a little strange, but keep in mind every iPhone launch before this year has been at that event. In fact, it's entirely possible the timing of this year's iPhone launch had more to do with manufacturing difficulties than anything else.
Keep in mind this is nothing more than rumor and speculation for the moment, but of course, given Apple's policy of strict secrecy, that's about all we can expect until a new iPhone is officially announced.