A bright and happy Meredith Grey had severe ramifications for Addison, most notably her marriage never broke down and she never moved to L.A.
Unlike her original timeline counterpart Addison Montgomery-Shepherd appears to have moved to Seattle with her husband Derek. Somewhat happily married, Derek does not have an affair with Meredith and instead starts a family with Addison. In the final scenes it is revealed that Derek is not the father of Addison's baby, but Mark Sloan. Still straying away from the original timeline Addison and Mark plan to move back to New York and raise their child together.