The topics (Exam Domain Areas) covered on the QlikView 12 Data Architect Certification Exam are the same as the QlikView 11 Developer Certification Exam, but ALL of the questions are new. There may be some slight differences for business analyst concepts in QlikView 12, but overall concepts of data modeling did not change much.
When/if you decide to upgrade your certification is your choice.
Similar to the QlikView 11 Developer exam, if you pass the QlikView 12 Data Architect Certification Exam, you will be awarded BOTH the QlikView 12 Data Architect and QlikView 12 Business Analyst Certifications.
For more information about this exam, visit the QlikView Certification web page; https://www.qlik.com/us/services/training/qlikview-certification
Certification Program Manager @ Qlik