Possibly.
Interesting decision to have the 'iPhones' rendered in different colors though.
While it sounds like a big device. It's really not.
If I didn't have a real one next to it, I wouldn't have picked that it was any larger.
Image
iPhone 2G for scale.
Looks like the same footprint of the iPhone 4 to me. Maybe we will see an edge to edge display (much like the first iPhone) but to the dimensions of iPhone 4's current antenna 'band'.
IMO That is what this image seems to be depicting. It STILL doesn't mean a complete overhaul in design though. I doubt a slimmer 'tapered' form factor is even possible unless the footprint grows in size, because the iPhone 4's tech is packed quite tightly as it is... AND as someone quite rightly pointed out to me once before, if it gets much slimmer, they won't have the room for a decent camera sensor.