First, there was Amy Acker (aka Angel's "Fred"). She guest-starred on Private Practice's Season 2 premiere (and next can be seen on Fox's upcoming Dollhouse).
More recently, you got Alexis Denisof/"Wesley."
Who will be the next former denizen of the Buffyverse to make an appointment with the doctors of Oceanside Wellness? It's Amber Benson.
What brings Buffy's Tara to Addison's work digs? Sources tell me she'll be playing a young woman who in the aftermath of being brutally attacked seeks not just medical care ... but perhaps something more.