Everything I have read is that Verizon will NOT provide the 928 with 8.1. I have a Nokia 928 and was promised 8.1 by the end of 2013. To this day, 25 Oct 14, no 8.1.
Verizon essentially doesn't do updates. They stopped updating my HTC Incredible 2 months before the end of the 2 year contract. My Incredible would no longer do text messaging. Verizon blamed it on HTC. Verizon was very willing to start another 2 year contract with a new phone. I picked out the HTC Rezound. Two months before the end of that 2 year contract, my HTC Rezound stopped accepting text messages. Verizon blamed the issue on HTC. Since then I have had a Verizon store representative tell me, that it wasn't HTC that stopped making updates, it was Verizon.
If I were you, I would run from the Nokia 928 AND Verizon. It takes good pictures but the rest of it may or may not be hampered by 8.0 who knows? But for sure, it's not a good phone the way it is. You can't talk and text at the same time, for example. Talk and check an app for the weather, for another example. Apps are being coded for 8.1; 8.0 and 8.1 have app compatibility issues. Windows 8.0 was NEVER ready for prime time.