Mike -
you are quite a man.
I'm sure you know by now that it's not the sperm donor that makes the father.
As to things to watch out for - gosh, pretty different from my sitch, but here goes .....
- it can take longer than you think for them to complete the process of breaking all ties with OP. There's a sort of emotional grieving process they have to go through - not so much for that person, but for the fantasy they had about how that R was going to be. Be patient, but firm - obviously it's unnacceptable for her to have further contact with the OM, but it might take her a while to write that definitive "I don't ever want to have any more contact with you" letter. In the meantime, try to make the R with YOU the fantasy that she wanted.
- Unless your W has already blabbed, I wouldn't talk with anybody about who's the bio father of this child. In most states it's still yours legally if you two are married when conceived. You might want to talk to an attorney about how to keep OM out of your lives.

Congratulations, and my hat's off to you.

Ellie