As we know you can divide the "big cake" (i.e. hardware managed by ESX) by creating ressource pools.

You create a ressource pool and assign cpu and memory ressources to that and can limit a group of users to use only a specific amount of ressources.

So, why the heck isn`t storage being managed in a similar way ?

The idea of ressource-pools in ESX looks immature this way....

Did i miss something (i.e. is there a proper way to handle storage as a ressource pool) ?

How can i keep a specific group of users from occupying a whole lun with VM`s ?

"assign them a dedicated lun" may be your answer - but - no - this is not the way to go, because this is managed outside of ESX.

even better:

http://www.vmware.com/files/pdf/Storage-with-VMware-vSphere.pdf , Page5

states:

Improved Storage Resources Control
As the scope of storage resources have increased significantly with large deployments of virtualization environments, so has
the need for greater automation and control of these resources. In the vSphere release, vCenter has been enhanced
with several new storage specific capabilities to help the virtual administrator manage these environments with a
higher degree of control. These enhancements provide administrators with proactive alerts and alarms to address issues
before they interrupt the availability of applications running on those resources. vCenter allows setting permissions and
quota limits on datastores, as well as per VM.

fine - but how ?