I would say they lean strongly towards evil (at least originally). Over the millenia, their natural tendencies were probably restrained by the influence of the other "good" peoples. Perhaps they are more influenced by their baser needs than the other peoples.
Giants haven't been mentioned very much so far, and I would prefer to have them as not inhabiting the Kessel - more a servitor race of the fiends.
The orcs who came to the Kessel and Imperialius's Hobgoblin race would be the exceptions to the rule, having overcome to some degree their fiendish origins.
Just my Canadian two cents.
I'll add them to the glossary later today after its been discussed a bit more.