New Configuration Maximums of vSphere 6.0: 

• vSphere 6.0 Clusters now supports 64 Nodes and 8,000 VM’s (Which was 32 Nodes and 4,000 VM’s in vSphere 5.5)
• vCenter Server Appliance (vCSA 6.0) supports upto 1000 Hosts and 10,000 Virtual Machines with embedded vPostgres database
• ESXi 6.0 host now supports support up to 480 physical CPUs  and 12 TB RAM (which was 320 CPUs and 4 TB in vSphere 5.5)
• ESXi 6.0 host Supports 1000 VMs and 32 Serial Ports. (which was 512 VM per host in vSphere 5.5)
• vSphere 6.0 VM’s will support  up to 128 vCPUs and 4TB vRAM (which was 64 vCPU’s and 1 TB of memory in vSphere 5.5)
• vSphere 6.0 continuous to support 64 Tb Datastores as same as in vSphere 5.5
• Increased support for virtual graphics including Nvidia vGPU
• Support for New Operating systems like FreeBSD 10.0 and Asianux 4 SP3 
• Fault Tolerance (FT) in vSphere 6.0 now supports upto 4 vCPUs (which was only 1 vCPU in vSphere 5.5)

I would like to provide a Quick Comparison table between the Configuration maximums of  vSphere 5.5 and vSphere 6.0:
For More Information please visit :-  http://www.vmwarearena.com/2015/02/vsphere-6-0-new-configuration-maximums.html