Aye... I THINK I found the problem, actually...

The default procedurals connect a reflection map (the sphere) to the reflection map node. They also set the Reflection Value to 1.000. However, the Reflection map is not connected to the Reflection Value node at all. So we have a map connected to map node, a value of 1.000 set to the value node, with no reflection map connected to it.

I have to test this yet - but the initial render after connecting the silly reflection map up to the Reflection Value node thus far shows none of that over-exposure of the procedurals. Give me a minute here and I'll double check. But I think this is the cause... o.O

~ Seliah