Know issues with vSphere 4 Update 2 and VMware View 4 PCoIP connections.
If you use PCoIP don't upgrade to update 2. More details found here.
vSphere 4.1 released now.
4.1 esx release notes
Whats new highlights:
* Storage IO control through shares
* Windows Failover Cluster support in HA
* Multiple VDR appliances
* Virtual Machine serial port redirection over network
* USB passthrough (and works with vmotion)
* Hyper-v VM import
* Memory compression
* AD integration for ESX hosts
* Multiple vcpus per socket.
* vCenter is now 64bit only.
Just virtualizing everything 4.0 u2
The fact that vCenter will only be installable on a 64bit OS in has been circulating or some time along with them dropping ESX completely in the next version in favor of ESXi which is more o a pain.
HP server - NMI driver required (or workaround implemented) for ESX/ESXi 4.1
HP NMI driver download
Oh and vCentre 4.1 isnt compatible with VMware Composer, so automatic provisioning of VMs wont work until View 4.5 is released.