I looked closer at my valve cover the other day and saw this oil seep from the top of the engine. Is this typical? Should I just wipe it off and forget about it?

This car is still under warranty - should I request a particular service? I talked to a dealership service advisor and he told me they wouldn't do anything about this.

Here's some pictures of the oil seep:

 

I have a few possible leads, from the picture check the oil cap, make sure it is tightend from the previous oil change, 2nd, remove the engine top plastic cove, check if there is oil near the spark plugs wires...if yes, then remove the spark plugs make sure they are not soaked in oil...It happend to my Audi A4, turned out to be valvle gasket leak, very costly..