vSphere 4.1: new features overview

I was in need of a shortlist of the new VMware ESX 4.1 features:

• VMware vSphere 4.1 can support up to 3,000 virtual machines per cluster and 1,000 hosts per vCenter server, both roughly three times the limits in vSphere 4.0. The number of virtual machines per data centre now maxes out at 5,000, which is twice the previous limit.
• Some enhancements to the vCLI command line interface allow for extra virtual machine controls
• Some enhancements to the host profile capability permit finer-grained control over ESX servers.
• Host lockdown mode and host power management have been improved.
• Virtual machine serial ports can now be accessed over the network
• Leverage Active Directory to control authentication to the ESX hosts themselves, rather than relying on local authentication or other methods.
• Compression over swap during low memory situations (less I/O to the disk)
• vMotion speed improvements
• enhancements to Distributed Resource Scheduler's VM affinity rules – can help in situations where not every host in a cluster is identical or connected to the same networks. For instance, if only a few hosts have connections to a DMZ network, you can create rules that force DMZ-connected hosts to vMotion only to those hosts.
• USB device mapping. It's now possible to map a USB device to a virtual machine and maintain that mapping even through a vMotion of the virtual machine
• Storage I/O control per VM
• Network bandwith control per VM
• a functional boot-from-SAN manager for ESXi that can run over iSCSI, FCoE, and Fibre Channel
• Virtual machines configured for FT can now play nice with DRS, for instance, allowing for load balancing of virtual machines that also require fault tolerance.
• Windows clustering services can now be integrated with VMware's HA functions, ostensibly providing a deeper level of failover functionality in Windows environments.
• SCSI locking not on LUN level but on Block level, a major improvement especially for VDI concepts.
• ….