VZ sure makes things complicated. I'm interested in getting the Storm and while researching the plans, I too had this question.
Here is what the current website shows as the available options once a Basic calling plan has been selected:
Blackberry® Solution Unlimited Data Usage Your Price: $44.99/month
Email and Web for BlackBerry® Your Price: $29.99/month
I figured that the $29 plan is similar to the one I have in T-Mobile but nowhere in the website or product details does it say that "Email and Web for BB" has unlimited data. Bu can anyone confirm this?