Sorry, but the Droid data will not work just fine. BBs are different. It is a totally different data package. You need the BB data plan if you want email, BBM, BB browser, app world, etc.
And since you are going to have it on Verizon, when you activate it, they will probably add the BB data plan.
One good thing though is the BB data should work on the Droid, but not the other way around.
From our FAQ: What do I need a Data Plan for? - BlackBerryFAQ
The Droid data would be considered a generic data plan for the BB and really limits what can do: How to use BlackBerry on Generic Data Plan - BlackBerryFAQ