VMware recently announced vSphere 5 will be coming July-August time frame 2011.
Three big new features will be included when it does come:
Just like you use DRS to help you manage the workload on your hosts, Storage DRS will help you manage the workload on your SANs. The essential workup is that you'll be able to group your storage into storage pods that you can allow Storage DRS to manage what goes where based on capacity. Pretty cool, if you are dealing with some complicated storage situations.
SRM Host-Based Replication
This buys you the ability to use SRM even if you have disparing storage at your different locations.
Network I/O Control for VMs
This allows you the option to reserve bandwidth for high-priority VMs when you've got a congested network. Very useful control to have, depending on your network layout and configuration.
Another anouncement that VMware has made about vSphere 5 - it's ESXi all the way. That's right, ESX will be discontinued in favor of it's lighter, tigher cousin. I mentioned that this was coming before, but now it's actually here. Hope you are ready for migration!
VMware won't leave you figuring it out on your own, though. They recommend that you start migrating off ESX to ESXi now in preparation for the move to vSphere 5. Here is their Info Center about it, and here is their Migration Guide.