Forgot to mention that our SAN is a PS4000.

Microsoft Cluster Services (MSCS) only allows 1 cluster node at a time to have access to a disk (volume on the Equallogic SAN). So, to make a 4-node active/active/active/active cluster, you'd have to run 4 shares; each off of it's own disk/volume/drive-letter and obviously with it's own data.

Understood.

Is there any way or any product that will be able to manage multiple connections to the same SAN volume? I was under the impression that Windows Clustering was the way to get me there.

How about using CSV in a Windows 2008 R2 cluster? From everything I'm reading it looks like this may work. Let me know what you think...

"A Cluster Shared Volume is a standard Cluster disk containing an NTFS volume that is made accessible for read and write operations by all nodes within the cluster."

"CSV operates by redirecting I/O operations from the node with ownership of the VM (Active Node) to the node with ownership of the LUN (Co-Ordinator Node)[1]. The IO Operations are passed between nodes via Server Message Block. All operations from all active nodes must be passed over SMB to the co-ordinator node, then passed again to the shared storage via Shared SCSI, iSCSI, Fibre Channel or other Multi-initiator storage method."

Also; CSV is only for use for storing VMs; no other applications/services can use CSVs.