I finally upgraded my 4 to a 4s earlier this week via a subsidized upgrade with VZW. I am in no hurry to get the whatever the newest model turns out to be whenever it is released. Mainstream media is only regurgitating rumors from the rumor sites so, while unlikely, it is possible that there may not even be a new model until Spring. And, regardless of whether it is Oct or Mar/Apr/May.. I may not like the design. For example, I enjoy the current form factor. If the device is noticeably longer in order to accommodate a larger screen, I would prefer to stick with the pocket friendly 4s.
Things like LTE, faster processor, better cameras, etc. do not interest me yet. I rarely use 3g data as I'm within wifi range majority of the time, even when I travel. My apps ran plenty fast on my 4 and I don't even notice a performance improvement on my new 4s. Finally, the pics I take are usually spontaneous pics for reference.
Anyways, I'm not about to put all my eggs in one basket quite yet. Worse case scenario, if the next iPhone model offers something that I can't live without, I'll just sell this 4s and use one of the other 2 remaining upgrades I have available on my plan. The other people on my plan are quite content with their current devices despite my numerous offers to upgrade their phones.