Migration from WCS 7.0 to PI 1.2 can be performed. If the customer wants to migrate data you need to first upgrade to NCS 1.1.1 You can download NCS 1.1.1 from Cisco.com if you have a valid service contract.
For the migration step involving NCS an evaluation license is sufficient. You can obtain an NCS evaluation license from http://www.cisco.com/go/license > Get Demo > Network Mgmt Products > Cisco Prime NCS Evaluation License.
Instructions for migrating data from WCS 7.0 to NCS 1.1.1 are available in NCS 1.1.1 Release Notes. Do not upgrade to NCS 1.1.2 as this release is not upgradeable to Prime Infrastructure 1.2. If you are ordering a Cisco Prime physical appliance (PRIME-NCS-APL-K9) be sure to select the NCS 1.1 image which you can later upgrade to Prime Infrastructure 1.2 after you have migrated your WCS data.
There is a post in the support forum which can be refered.
https://supportforums.cisco.com/docs/DOC-26972