There's no information on when Verizon will get the update beyond the fact that it's expected before the end of the year. Usually, Verizon is the last carrier in the U.S. to get updates because of their ridiculous testing process. Usually T-Mobile or AT&T see updates before Sprint on multi-carrier devices, so I'm surprised to see Sprint getting theirs out first.
Felt the same about JellyBean delay when I was using GNexus. But when it finally arrived the improvements were modest at best.
In my experience ICS on GS3 is far superior to JellyBean on any other device. And I'm running JellyBean-and the update- everydate on my Nexus7 everyday.