This is a tough one to answer. Is Coffe Paleo? In strict paleo terms it is not. It does not belong on the original definition of the paleo diet nor does it work even when you consider the more modern evolutionary template that the paleo diet uses.
Studies have shown that coffee consumption linked to better overall health. But there is nothing to say that the cause of that improved health is the coffee. Coffee on the other hand is used to mask various lifestyle issues that need to be addressed.
Is coffee paleo?
If you do really enjoy your cup of coffee black without sugar and creamer then it is okay. If you have to have it with creamer then you will need to think twice about whether you really like the coffee or using it as an excuse to have something creamy. The same goes for people who need it to counter bad sleep. Just make sure you are not using coffee to make up for lifestyle problems (like bad sleep) and you should have no problem.