It seems pretty clear that the hopes and expectations of DS fans on here are all over the map.  Unfortunately, as the adage goes, you can't please everybody.  There will be some who don't like the fact that they didn't explore Barnabas' relationship with his sister.  There will be some who are unhappy if they don't flush out Julia's romantic interest in Barnabas.  There are already some who don't like the fact that the series is being set in the '70's (although I do believe there are some logistical reasons for this, vide infra).  To me, this movie will represent Burton's interpretation of Dark Shadows, and I believe I'm capable of enjoying that without requiring his interpretation to fit perfectly with mine.  I remember as a kid rooting for Angelique and Barnabas to end up together (that is, before I developed a crush on Kate Jackson's Daphne), and it really wasn't until years later that I discovered others felt that way about Julia and Barnabas.  I personally will be fascinated to see where Burton takes it, and I welcome something of a fresh take on things.

As to the '70's, I know somebody pointed this out before me, but I think it's the only way they can plausibly use the "cousin from England" aspect.  In 2011, it would take no time on the internet to debunk Barnabas' story, and there would be no way to keep the prospects of a vampire local in the days of YouTube and cell phones with cameras and video capabilities.  And it still leaves open the prospects of a time travel forward element that will age better than when Barnabas and Julia traveled forward in time. 

This appears to be a little dated and largely restates what's already been reported, but I hadn't seen it posted here:

http://blogs.indiewire.com/thompsononhollywood/2011/02/16/directors_keep_it_in_the_family_dark_knight_rises_dark_shadows/#

In a two hour movie that will include Barnabas, Julia, Elizabeth, Willy, Angelique and Victoria Winters, I won't be stunned if we've pretty much run the course of the major players in this version.  There's only so much screen time to go around.  I suspect that characters such as Carolyn and Roger will be minor in this adaptation.