Apple's last iPhone release--the iPhone 4--. That was when Apple stuck to a pretty consistent schedule of unveiling a new smartphone model every summer. The iPhone 4 has retained its spot as the newest iPhone on the block for an extra four months, but it's pretty apparent that a successor is waiting in the wings.

If you don't pay attention to the Apple rumor mill, keep up the good, sanity-maintaining work. But if you do, you've no doubt heard rumors that when Apple finally unveils a new iPhone, it will present two models--an iPhone 4S and iPhone 5.

I don't really buy that, and it's not because I have any inside information. Rather, I'm just looking at the clues Apple dropped in its invitation to the October 4 press event. The Calendar icon shows the event's date; the Clock icon shows the event's start time; the Maps icon shows the event's location (Apple's Cupertino headquarters). Numerous online sleuths have interpreted the fourth icon--the Phone--as indicating that Apple will introduce just one phone, thanks to the otherwise unnecessary big, red badge on the icon's corner. That seems like a reasonable interpretation to me.ull of--

So we can expect a phone (in addition to more information about the already previewed and , of course). But what can we expect from that phone? Or, more to the point, how does Apple improve upon the success of the iPhone 4 which, aging though it may be, still racked up record quarterly sales between March and June this year? Does it do away with more physical buttons? Improve the earbuds? Make the even more Retina-ier?

Here's one man's take on what could happen, with predictions broken out into three categories--Definitely happening, maybe happening, and probably not happening. Feel free to point and laugh at my prognostications or, better still, add some of your own.