If you've ever had your Mac icons in the toolbar and/or menu bar disappear then this might help.
In my case it appears that it's linked to VMware 5, my icons disappeared shortly after I upgraded from VMware 4, whether it's just a coincidence or not I don't know.
Reboot into safe mode (hold down shift key on reboot)
Once you've logged in all your icons should be back, then just reboot again without holding anything down and your issue should be fixed.
Also note that creating a new User also "fixes" this issue, but it's far from an acceptable solution.