On another thread I saw Natalie waiting to come in when the departing evictee opened the door to depart.
Julie said Natalie will be unveiled "live", but there are any number of ways that could occur.
I'd like to see something along the lines of the houseguests, perhaps after the eviction, gathering outside for the HOH competition. Adria has convieniently forgotten to bring a required prop with her, and stern Julie sends her in to get it. A couple of heartbeats after Adria goes inside, she reemerges, only she is wearing a completely different outfit. Julie speaks to "Adria", drawing attention to her to see just how long it takes the others to notice somethings different. When they don't, which they won't, Julie asks "Weren't you supposed to bring out the 'gizmo'?", whereupon Adria emerges from the house saying "No, that would be ME, Julie", and we have time to see pants wetting on the part of several HG's and Cowboy and Drew backing off for a little tearfest prior to a timely commercial break.