[Galadriel55]

I second Boro, this is a very interesting topic.

I agree with what has been said, and "opportunist" seems quite a fitting word to describe Sauron.

It's really not that difficult a choice for him: either you work hard to do the near-impossible of bringing your old master back, or you become the big bad bully yourself. Knowing Sauron's lust for power, his choice is clear. I doubt he ever felt any devotion to Morgoth beyond the basic "while he's there he gives me power" feeling. So I doubt Sauron had any great loyalty in the first place.

I like the sound of the idea that Sauron's Morgoth cult is really subconsciously worshiping "Morgoth's Ring", not the individual himself.