It sounds like you've weathered the initial shock well, and have adapted to the polyamorous prospect rather quickly (in relative terms). I think you should encourage your wife to continue to explore this new relationship she has with Jane, a little at a time. It is great that you and Jane get along also.
What about John Doe, is he okay with these new developments? Do you have much contact with him?
Overall, your situation sounds rather positive, despite the initial hurdles. I wish you and your wife (and Jane and John) the very best.
Love means never having to say, "Put down that meat cleaver!"