I've overall really been enjoying the main series. There's a lot of great scenes for Julia in that series, and the writing subtly reflects a pro-Barnabas and Julia subtext - althought it's less subtext and more blatant really, but in a tasteful way.

I could see Karen Black playing any of the roles Marie Wallace played. I think she'd have been well suited as maniacal Eve, mad Jenny, or Megan. Not that I'd want to lose Marie Wallace who is wonderful, but those are the roles I think Karen Black would be best suited for.

Sam - William Shatner ( I've long thought he'd be perfect in the role, he reminds me of Sam, I could easily see him playing a boozy, bitter but good humored failure, and I think he'd hit the right notes in his relationship with Maggie, that he adores her, but depends on her to look after him.)
Joe - Tom Welling ( he certainly has the wholesome good looks for the part)

Jean Simmons's Liz was really underdeveloped. We know so little about her. We know nothing of her husband/Carolyn's father. Was he dead, did he leave her like Paul in the original series? The whole reclusive story was dropped, and I don't remember there being the business and financial problems that were important in the tv series and movie. Liz and Roger had a niece Daphne, but we know nothing more about their family. Presumably they had another brother. The mystery of Victoria's origins and Liz's involvement also were dropped on the tv show, but one of the Innovation comics, I think it was the last one, did have Roger ask Liz when she was going to tell Vicki that Liz was her mother. If the comic series had continued we probably would've learned about her past in that format anyways.
But on the tv show there are no hints of Liz having marital problems, a secret illigitimate child, her torment over thinking she had killed Paul, and yes, there is no subtext in the performance for any of that. I don't mean it as any criticism of Simmons, she played the character as written, and none of those elements were part of the 91 series, but her character didn't get as much depth because of it, although I still liked her. 
I feel that she had more to do with Naomi at least, with a cold husband, the deaths of two children and her son the vampire, and going mad.
Even in just two hours Pfeiffer's Liz got a lot of development, she had a crumbling family fortune she was trying to hold togather single handed at the begining, a troubled teen with a secret and a disturbed nephew, an odd but mature and believable friendship with Julia, and her character's ruthless traits as she accepted a vampire, turning a blind eye to the deaths Barnabas brought about, because she needed him. Pfeiffer really was one of the best parts of the movie imo.

KLS is probably in her 60s I'd think, just still in the right age bracket to play Liz. But that ship has sailed.
Joanna Going is certainly beautiful and classy enough to play Liz, but she's not really a big enough name to fill the historic qualifications.
Veering the topic slightly, it occured to me that I think Anne Heche would make an interesting Julia, and I think Zachary Quinto would be amazing as Barnabas.

PT Sabrina died. This audio is set in real time with real time Cyrus and Sabrina.

If anyone is interested Big Finish is doing an audio in the next few months with Cyrus and Sabrina in real time 1973. I'm pretty curious how that will play out.

I read that Amazon is going to start selling specially licenced fan fiction from Vampire Diaries. There is a huge list of restrictions, but from what I understand this is going to be real fan fic, written by fans, not the typical media tie ins.
I find this really interesting, but the real question is if they'll allow slash, which is one of the biggest segments of fan fic.
I'm guessing this is all spinning out of 50 Shades of Grey starting life as a Twilight fan fic.