If you currently are with Verizon and are looking to upgrade your device to a Samsung Galaxy S3, take note: if you pre-order the device before June 28, you will keep your unlimited date plan, which Verizon are otherwise axing under their new Share Everything plan for all other cases.
Samsung Galaxy S3 an exception when it comes to upgraders with unlimited data plan
In case you are dubious about this claim, do be reassured that the information came right from the top. DroidLife were told by a ‘top communications director’ at Verizon precisely that if you pre-order the Samsung Galaxy S3 prior to June 28, your plan will remain the same, and you can stay on your current contract (you cannot move on to a new contract and get the same deal).
This claim goes against complaints from users who had been informed by Verizon that they would no longer have unlimited data on their plan, but contrary to this, you will be able to keep your plan. The Shared Data plan launches in the next few weeks and you are contracted to your agreement regardless of when you do actually receive it.
This new statement from Verizon should clarify matters for concerned users and hopefully has arrived just in time for everyone to buy the Samsung Galaxy S3 and keep their plan.
[source]
