That sign looks just like the one that was (is?) at the Collinwood exterior set.
This time this tweet came up that does indeed mention DS:
tomwarren
Johnny Depp filming Dark Shadows in Beckenham Place Park tonight/tomorrow
8 hours ago
Last time only tweets made during the past 4 hours came up and then Twitter displayed a notice that "Older Tweet results are unavailable." That's been happening a lot lately. But not this time.
And there are actually quite a few tweets if one searches using Depp's name - though all they say is that he's expected to shoot there. Some also say to post photos at the site jimbo linked to, so it'll be interesting to see if anyone manages to catch Depp or any of the other stars, or if it will be like the Collinwood exterior set where everyone was kept at bay by security guards and German Shepherds...
In other Twitter news there's this puzzling tweet (which was made in response to a July 6th tweet about the Collinwood exterior set):
heather_p32
@TimBurtonNews I live just nearby & annoyingly was pencilled in to work on "Dark Shadows" too.
2 hours ago
Why would working there be annoying. Many of us would practically kill at the chance!
291 days 2 hours 36 minutes 5 seconds until the day the Depp/Burton DARK SHADOWS is released(ET)!!