Seeking Alpha says shortages are in fact both supply issues and more than expected demand.

[VisceralMonkey]

Nokia: Is The Lumia 920 Selling Well, Or Encountering Supply Issues? - Seeking Alpha

tldr: Says production woes are having an impact but that higher then expected demand has pushed the Lumia 920 into its current out of stock status. Advises "Buy" on stock.

 

[MaxPower203]

Is this an American thing? I got one from Rogers in Canada and there was no shortage from what I could tell.

 

[dkp23]

What is holding back the sale of these phones is nokia itself. If it is a strategy, shame on them, but im thinking it is not, and the issue is supply. I think it is not due to demand so high that they cant put out devices fast enough, but something is wrong in the manufacturing stage that is resulting delays in these devices.

 

[Laura Knotek]

Is this an American thing? I got one from Rogers in Canada and there was no shortage from what I could tell.

No, it sold out in Australia (Telstra) and UK (Clove) also. Nokia Lumia 920 sold out at both Telstra and Clove | Windows Phone Central

 

[ColeHarris]

Whatever the problem is I hope they sort it out ASAP! They're loosing customers every minute that goes by that you can't actually buy the dang phone.

 

[beej]

Seriously. I have a family of four ready to buy.

 

[socialcarpet]

You can't always control every piece of the supply chain perfectly.

I've been wanting to buy a Kindle Paperwhite for 2 months, for example.