"When I saw the show in DC & NYC, I don't remember there being any ghosts before the show started, or during intermission. They may have entered the stage right before intermission ended."
Nealb1: There wasn't any ghosts before the orchestra started (though if you watch carefully, you can see both the one behind the curtain that goes up and the one that comes from behind the stairs get into places about 30 seconds before the overture starts).
The intermission ghosts (there are three) have been hanging around during the whole intermission ever since the DC production (I should know, I used this time to get better looks at the costumes through my binoculars, though I felt a little bit like a lecher). And I noticed in the LA production (I'm not sure of the Broadway mounting, since that's the one place where I didn't see the show) that they added a couple of more ghosts. One during the "Rain on the Roof"/"Ah Paree"/"Broadway Baby" montage (I think she appeared during "Ah Paree"), and one during "I'm Still Here".
I forgot to add in my notes from when I saw the show in LA a couple of Sundays ago that I'm glad the ladies remember their purses now at the end of the production. And I really noticed Elaine Paige's back phrasing during "I'm Still Here", which I didn't notice the two times I saw it in DC (though people have been complaining of it since then). She also held the second to last line ("and I'm heeeerrrreeeeeee") which made her phrasing for the last line really weird. At least she sings it well on the cast album.
Xanadu! Can't cry on cue!