I came across a site talking about certifications 2013, is not official but it seems very likely.
As expected, 4 certifications are planned for development SharePoint 2013.
2 web oriented and 2 SharePoint oriented.
Exam 70-488– SharePoint Rest ( Exam Number Confirmed, Name not confirmed)
Exam 70-489– SharePoint Collaboration ( Exam Number Confirmed, Name not confirmed)
SharePoint Beta should be available in April (alpha release in July).