Even before reading this article I was pretty convinced to stick with my iPhone 4, especially after upgrading to iOS 5 (because it is just amazing, right?)
I honestly think upgrading to a 4S from a 4 is pointless. The only thing you are really upgrading to is a faster processor, 3 megapixel better camera (wooopie), better video recording, and Siri (which most people only use to ask random questions rather then for actual purpose).
Don’t get me wrong, the iPhone 4S is amazing and I would get it if I had an extra $450 laying around, but I am content with my 4 now and I will just wait it out till they come out with the 5. If you have a 3 or a 3gs iPhone then getting the 4S compared to the 4 is totally worth it, but going from a 4 to a 4S is almost the identical thing.