I don't really see the difficulty in bringing Blithedale to the screen. As far as the narrative structure goes, I think the style of "The Shawshank Redemption" would do the book justice. I haven't seen the movie The Great Gatsby, but I'd think that between the two a good model for Blithedale could be produced. I think that there may have to be some enhanced action or more visual stimulation for a modern audience (I am not talking about natural disasters).
As for the stories within the story (Veiled Lady, Old Moodie's story) these could easily be accomplished with flashbacks (or cuts) to the event. My only debate (other than the cast) would be whether the story was told by Cloverdale as he is writing it (and then blends into a narrative voice overseeing the action) or if it would strictly be his voice throughout as if he were telling the story orally. The only part this would make a difference in would be the beginning and, more importantly, the end. How to deliver that last line...
Ok now that I did my penance, here's my cast(s):
Current:
Cloverdale- Johnny Depp
runners-up: Tom Cruise, Ray Liotta, Kevin Bacon, Ed Norton Jr, Hugh Grant
Hollingsworth- Tim Robbins (I can't beat Gabriel Byrne)
runners-up: Val Kilmer, Liam Neeson, William Hurt
Zenobia- Linda Fiorentino (Last Seduction)
runners-up: Madeline Stowe, Barbara Carrera (she has the look and figure), Sigourney Weaver,Sharon Stone, Kim Basinger
Priscilla- Heather Graham
runners-up: Claire Forlani, Alicia Silverstone, Gwyneth Paltrow, Mira Sorvino, Alyssa Milano
All-time:
Cloverdale- young Jimmy Stewart (quintessential voyeur)
Hollingsworth- young Paul Newman
Zenobia- young Liz Taylor (whoever said her, thank you)
Priscilla- sober, Dorothy-era Judy Garland
Beverly Hills 90210 (withstanding kinship):
Cloverdale- Brandon
Hollingsworth- Dylan (ok, so it doesn't quite fit)
Zenobia- Brenda
Priscilla- Kelly (early years)