I felt so empowered to have all my wits about me and not be afraid or nervous or going bonkers w/my emotions

Yes, that sounds great. Just as you would've treated him even if you didn't know he was the OM. It sounds like you've made some great strides in yourself during these last few weeks. Good work.

My question is this, now what?... Do I wait to see what happens?

Why not?

Do I let my W know what I know? (I'm guessing not.)

I don't know what knowledge you're alluding to, but I'd agree with you.

I've been dark (save for stuff about the kids) for about 6 weeks now. For some reason I feel the urge to some out of the dark, but don't know what to do or say. Any suggestions?

What's fueling your urge? Is it lack of results during these six weeks? Has she not initiated contact? If you're not seeing results in this time, you may want to surface a wee bit. It's just as important as anything else that the WAS gets to see a positive, spirited, happy you. Someone they want to be around.