To be completely honest, I will wait for step 5. Not because of anything huge in particular: there are many little things in step 4 that just doesn't fully convince me for the cash I will have to pay (portrait mode, TV Out, battery, MfE, HW/form factor, etc). And if step 5 turns to be meh, I will just buy step 4 which should be cheaper and better by then.

I will add that in my particular case my ratio of cost/benefit is very exigent: to get an unlocked Nokia device, I have to travel from my country to either Chicago or NYC, the nearest flagships stores. No other reliable way of getting my hands on a device.