They might be for now but if you look at the leaked ad for the new plans, it says that the everything data plans do not have the "Sprint unlimited gurantee" which is a feature that Sprint says gurantees unlimited for the life of the line of service, meaning unlimited data on our curent plans may end at some point...
More complete picture than CNET at this link:
http://www.intomobile.com/2013/07/10/sprint-may-changing-its-prepaid-plans-according-leaked-photo/