They really just need to make a smaller 6S. Not give us a "C" (cheap) like last time with year old hardware. If it has the same internals as the 6S just smaller I would bite. I also would bite if they decided to throw 6 specs in, but price it around $450-$500 out right.
I doubt that would happen since they already have people paying $650 to enter the iPhone world. If they price it the same, it needs to be the same just smaller. I think apple would be surprised at just how many people still want a phone sized phone. I wouldn't even mind a plastic back.
I love to see the colourful 5C's everywhere. I also love to have the fastest, most capable version of the iPhone in my pocket, which will always be the standard model.
Design-wise it will probably be much more like the iPhone 6 design. If it's anything like the 5C is designed, it will resemble a bigger, plastic iPhone 5 design. They specifically said a bigger iPhone 5 wouldn't be comfortable to use, hence the rounded (rounded glass and back to create a overall round shape) iPhone 6 design. I'm curious if that's possible to recreate with plastics (in a cheap way...).
That design... doesn't agree with me. It looks very reminiscent of the 4th generation iPod touch, but I also see the 5th generation at the same time. It's a little hard to tell because the blue doesn't offer much contrast and creates the illusion of there being very little bending radius, which is why it reminds me of the 4th generation. While it wasn't uncomfortable to hold, I've become very fond of the rounded sides on the iPhone 6 and 6 Plus and I'd like Apple to continue that trend.