Speaking of battery, I would love to see wireless charge on it.
I know this is a space consuming featurebut it can come in handy.
Speaking of un-practical trends (because oneDevice is all about this), I would like to have a back cover in another material than glass. This is a fragile and slippery material. The best experience I had on my numerous smartphones was the Motorola razr HD Kevlar back pannel. Soft, grippy, classy and very resistant.