Radiator Leak- How bad is it?

[docfeelgood]

I just noticed this for the first time, when I was changing my oil this afternoon... My coolant overflow tank is empty, it is a cool 40F degree day-the fluid within the core appears to be normal- and I drove the car for a few minutes till the engine warmed up- and the cab engine temp gauge reads its normal level- Yet, I have this nice leak.

I'm planning bringin it in for a closer look- but if anyone has come across a similar situation, please post.