Next time I want to show something in the Magento frontend just for admin users, Alan Storm’s module
Magento_CrossAreaSessions will come in handy! This is a topic that caused me headache in the past. Read more at Magento Quickies or get the module from GitHub: Magento_CrossAreaSessions
Background: Magento separates adminhtml and frontend sessions strictly, so it is not a trivial task to access the backend session on a frontend page.
The module allows reading of raw session data and processing of ACL rules, which is good enough for most cases.