I think the Phone is coming sooner then fall. With the leaks we've gotten, you could see the phone in June/July with iOS6.
I think last year was a fluke with the push back into October...they had some sort of issue with either supply or a component or this metal back/casing on the new phone wasn't ready. I really think the 4S was a fall back plan when they couldn't get this new design ready by when they wanted.
I think we're back to a early summer release.
Apple had a monster of a holiday quarter, and it was all thanks to the iPhone. The iPhone is in the fall to stay. Summer makes more sense for Mac releases, since it comes before the school year, and obviously Apple seems to like keeping the iPad as far away from any big shopping days as possible, both to boost their numbers throughout the year, and to keep things moving well through their distribution channels. They can't have the iPad and iPhone too close, or they just can't ship enough units of either. Since Apple's not going to give up on the best time for gifting shiny trinkets, and there's no sign that the iPad is getting moved to fall, that leaves iPhone in the fall, iPad in the spring, Macs in the summer, and nothing in the winter.
Okay, so you don't have to take my word for it, look at what we know about iOS 6. That's basically... almost nothing. Apple won't ship the next iPhone with anything less than the new iOS, and the new iOS won't be ready for quite a few more months. We'll get some hints when the developer releases start coming out, possibly as early as WWDC, but it will take time before bugs are worked out, features are set in stone, and it's stable and efficient enough to ship. Apple
could release a new iPhone now, and then hope that everyone upgrades to iOS 6 when that comes out next fall, or they could wait until the software is ready and then release hardware designed and optimized to run it, and make sure every user has it out of the box.