There's another thread talking about this right now. VC to VM Console SSO/Authentication.
http://communities.vmware.com/message/1090180
Think of the VM Console the same as attaching a KVM (Keyboard, Video, Mouse) to a VM, in the same fashion as you would on a physical box.
The VM Console is behaving much the same way. You'd have to modify "KVMness" of the VM Console to plugin to the guest, using some type of app/service that ties into the logon process of the guest.
Keep in mind, if you do find success doing this, you'll need to limit your guest's number of active terminals to 1, otherwise more than 1 user can be attached to the console at a single time.
Add this line to your .vmx file, and it will limit it to 1 console session:
RemoteDisplay.maxConnections = 1
Cheers,
Jase
Jase McCarty
http://www.jasemccarty.com
Co-Author of VMware ESX Essentials in the Virtual Data Center
(ISBN:1420070274) from Auerbach