...This means there are now millions of devices connecting to Verizon's 3G network using an authentication scheme Verizon hasn't previously utilized on that network, and (major) hiccups are occurring as a result.
The "hiccups" are authentication failures - the new scheme is extremely particular about failed attempts to authenticate a device. Your device authenticates regularly, "checking in" with the network to ensure you're still supposed to be connected. When your device fails to authenticate on the network (for any reason - and there are a gamut of possibilities), Verizon will kick you off the data side (not voice, though), either 3G or 4G. At this point, you notice you no longer have a data connection, and throw your phone at the nearest wall.
The severity of the problem can depend on your device. Some devices are more likely to re-attempt authentication immediately, and ten or fifteen seconds later, you're good to go. Some won't - and have to be forced to re-authenticate by switching in and out of airplane mode. Some won't even respond to that, and have to be powered on and off. Our speculation in regards to the varying severity is that it more than likely depends on how aggressive the phone's battery conservation software is. If a device loses connection, it may think it's in a "fringe" coverage zone and stop attempting to reconnect to the network to avoid wasting battery. It could also be that the device's software is just poorly written to deal with such regular failed attempts to get network authentication.
