A truly unexpected would be a phone with an eInk display only. And with one very good camera. I enjoy my pictures taken on the phone mostly on my computer, so I use my phone only as a preview :)
I agree, such a phone would be awesome. It's a shame the Iridigm/Mirasol "butterfly wing" technology hasn't become viable after all these years (yield issues AIUI), because that would be almost as efficient with full color and contrast. Couldn't play games on it, sure, but everything else would be fine.