I think I'll post a summary here really quickly on this in regards to Verizon getting a 920 variant.
1. If you cannot wait to get a 920 (or variation) then AT&T is your only option. They will be the only one with the phone at launch and they will be the only one confirmed to have it then. They have an exclusive window with the top end Lumia device and paid Nokia to get it. Verizon cannot announce anything until AT&T has had the 920 on the market for at least 21 days. Verizon also would be unlikely to do so anyways as they do not announce phones more than a week out generally, as I have stated and has been seen.
I've experienced this one first hand talking to my contact at VZW. About a year and a half ago, I was looking for a phone. I had heard rumors of the HTC Trophy hitting VZW and I was most interested in getting a WP device, but also looked into the Droids. The HTC Thunderbolt had just come out and LTE was very intriguing, though had issues. The most alluring device that was rumored to me at the time was the Droid Bionic, a dual core LTE device that was SUPPOSED to hit only about a month after Thunderbolt. The leaked roadmaps said so - but my source said it wasn't going to happen due to technical issues with the phone, specifically the problem of LTE switching off to EVDO when it lost the LTE signal but never going back to LTE until you reset the phone. Motorola was and is a strong partner with VZW and neither wanted the Bionic released until they solved the problem. My source said it would be delayed until September. Sure enough, that's when it hit - and I got a Trophy, that was also delayed as VZW was waiting for NoDo.
The one exception I can recall to the launch window rule was the Motorola Droid, IIRC, but that was largely because of many looking for a Verizon response to the iPhone.
2. Phone launch dates are often in flux. This is why Verizon generally does not announce until they have stock. They do not trust manufacturers to deliver on the dates they set and refuse to have egg on their face because of it. Verizon's stance is that their are plenty of great phones in the world and all of them are worthless without a network. Verizon feels (and I agree, I'm a user and biased, though) that they have the best network. They also don't like carrying phones that are not ready for primetime because that also plays into how a network is viewed. They shy away from first gen stuff and let other people deal with the problems in regards to the phones. They will always be bold when it comes to the network, but they prefer reliability in the phones they stock. This is one reason why they turned down the iPhone initially, coupled with Apple's monetary demands.
They didn't release an Android phone until the OS had been out for a year and it had Android 2.0, IIRC - at least 2.0 was pretty close to ready.
But remember that phone dates are very rarely set in stone. WP8 was expected to launch about a week earlier than it will. Verizon was initially told that WP8 devices could be made available alongside Windows 8/RT devices on October 26, so that was the initial expected launch date through much of the summer. Their original schedule was built on this supposition and might have to move by a couple of weeks due to it.
3. Whenever Verizon launches, expect them to only carry two WP8 devices to start. They don't like to launch more than two phones at a time. Right now it appears that the HTC 8X and the Nokia Lumia 822 will launch, though that may change to the 8S instead with the Lumia 822 launching with the 9XX variant. Samsung is supposed to have a CDMA version of the ATIV S for them and the plan was to launch that around 2 weeks after the WP8 VZW launch. Then around 2 weeks later we are to see the Lumia 9XX and, as stated above, possibly the 822.
Do not expect to hear about these phones until a week before release. Depending on HTC, the heads up announcement could come a week before availability on Halloween - OR it could be a week after that. Like I said, the dates are not set in stone and it all depends on delivery from the handset maker. Verizon is not like AT&T, who tends to launch on Sundays. They often favor mid week launches but are flexible.
So if you are impatient for a 920 and are out of contract (or already with AT&T), then I'd advise for you to go with AT&T. They have a good network and I think you'll be very happy with the phone and the network.
If you want to be with VZW and are willing to wait at least a month then you are likely to be rewarded. I'm not eligible for my upgrade until mid-December, so I can be patient. Frankly, my Trophy works well. It's not a flashy phone, but it gets the job done. I could wait until my contract actually ends in March as well and bask in some quad core goodness too - if the phone launch schedule doesn't flex too much. They expect quad core WP8 devices by the end of March - and one is listed from Nokia, just so you know but that list is still considered very tentative. As I said, phone releases are not set in stone and Verizon will not release a date until they have enough phones in hand to sell. Before that you're out of luck.