I feel like Nokia will do the same thing HTC did. If by WP8.1 they're still using the Nokia brand, I think they might start over from scratch. HTC went from the HTC Evo 3D to the Evo 4G, One X, One SV, One X+... all to come to the newest HTC One. Simple: brand name + phone name. If Nokia decides to do that with 8.1, it'd be easier for many consumers.
"Oh, what kind of phone is that?"
"It's a Nokia Lumia 1020 Windows Phone."
It just seems like a lot. Ditch the Nokia name, keep it to the Lumia line. Something like "Lumia 10" or "Lumia 9" would be perfect. But hey, that's just my opinion/prediction.