Great White Paper here for those of you transitioning from 5.5 to 6.0 and want to know what the differences are:

http://www.vmware.com/files/pdf/products/vsphere/VMware-vsphere-60-vcenter-server-appliance-55-60-comparison.pdf

For me the major difference is VMware have dropped the Virtual Appliance Management Interface (VAMI), which makes sense as why would you want to manage your virtual environment from one browser url and administer your appliance from another! They’ve rolled all the configuration of the vCSA into the installation wizard, and also all the administrative aspects into the admin section of the Web Client.

I always found it a pain to fire up Web Client at https://<vCenter Server>:9443/vsphere-client and then the VAMI at http://<vCenter Server>:5480

=)