Here is a taster of some of the new features VMware is cooking up for VMware VI4....
64bit VMKernel and Console Operating System (COS)
Clustered vCenter Servers
ESX/ESXi Host Profile Management
Cross-host Virtual Networking
8-way Virtual SMP
Virtual Machine Fault Tolerance Across Multiple Hosts
VMs and Media Library
Alarms on Physical Hardware Faults
Access Control on Storage Resources
Configuration Change Tracking
Full Support for Local SATA storage
Thin Disk Provisioning
256 GB Memory Limit Per VM