Here's how it is going to work.
Developers build their devices and send them to Verizon. Verizon promises it will take no more than 4 weeks to test the device, and of course there is a fee for testing. It will be returned with a pass/fail stamp. There's no in-between. Verizon didn't say if it will offer pointers to developers to let them know where the weaknesses are. If the device passes, the developer needs to register it and it will be given a serial number. Sounds straightforward so far.
If the developer wants to sell the device, he/she has a couple of different avenues. The developer can retail it on their own, with all the related expenses their burden to bear. The developer also is responsible for any tech support related to the phone. The developer also can choose to become a mini-MVNO by buying minutes at wholesale prices from Verizon and then selling the minutes (and device) to you. Verizon also is working on a custom model for accommodating custom wholesaler businesses.
At this point, if a consumer buys one of these approved devices, they will need to activate it online. Here is where you will be guaranteed a working device. You will have to enter the serial number registered to the device. If the serial number isn't registered with Verizon, the device won't receive network access. If the device is bought via the wholesale model, the seller will be responsible for activating the device, just as it would be in any regular Verizon Wireless retail shop.
Once everything is activated, customers will presumably be able to download whichever applications they choose and also can select the extent of the relationship they desire to have with Verizon. That means there are no contracts, and no early termination fees.
How soon will all this happen? The certification process will be up and running by the end of this month, and the entire shebang should be operational in the second half of the year.
OK, this is great. But how many developers are going to jump at the opportunity to make devices to access Verizon's network and then sell them? Is it going to be worth it for the developers? And what about the user? Yes, they get access to Verizon's network on a device they (presumably) really want to use, but what quality assurances do they have? How far will the mobile ecosystem really go to support these nonofficial devices and applications?
For the moment, all we can do is wait and see.