As I mention in that review, I kept thinking of Eliot's predecessor Jane Austen & successor Edith Wharton while reading it, and in fact kept seeing the characters in those terms. So I've set out to cast the Middlemarch characters, not with actors, but with Jane Austen characters, which seemed like a fun exercise a la breaking Shakespeare casts into Commedia Dell Arte archetypes. Anyway, here goes...
Will Ladislaw, Doctor Lydgate and Reverend Farebrother, due to their ambition and complex social problems, should probably be cast from the Edit Wharton Cinematic Universe rather than the Austen one. Whereas Mayor Vincy, Caleb Garth, the Bulstrodes, and many others of the "business men" are much more like characters from Dickens.
Looking over the list, it's clear that Dorothea & Rosamund really need to team up for Bennet Sisters Power, which makes sense as Middlemarch gets considerable tension (some of it comic) out of almost throwing those two heroines together but then making them miss each other (because if they ever really compared notes, they could sort out about half the town's problems). Will Ladislaw is sort of the Nemesis of the Bechdel Test here, because he keeps being there whenever these two meet and creating a melodramatic situation where they can't talk (except perhaps about him).
Speaking of Bechdel, my biggest disappointment with the book is that the friendship of Rosamund Vincy & Mary Garth gets dropped halfway through, without any reason I can see. This is really unfortunate given how scrupulous it is about other relationships and how they pull back and forth (so much so that I found it beneficial to read the first 80 pages twice so that I could catch people's first mentions & appearances better).