Yesterday VMware changed the contents of the vSphere VCP510 examination.
Questions where the answer between v5.0 and v5.1 may be different have been replaced or modified so that they are version agnostic.
It will not be necessary for existing v5 VCPs to take the exam again to reflect the new version and there are no changes to the registration requirements. VCPs holding the VCP5 or VCP5-DV will not need to take this exam to retain their status.
You can find the revised blueprint at the following location: