"Weird," not "Modern"
Matt Finch writing here, with a bit of a blog-like post about the nature of the Blight. These are my opinions, and Richard might actually disagree with my conclusions, so take them as you will. I wasn't involved in the original writing for the Blight, so these are subjective reactions to my initial "cold read" on the book.
A few people are worried about the apparent "Victorian" feel of the city of Castorhage, concerned that it might have too modern a vibe for a traditional fantasy campaign. Fear not! The introductory materials we've shown, and the fact that we're using some photographs, can definitely create that impression; but that's because teaser material almost by definition gives only a surface view of things.
It's absolutely true that Castorhage has a unique feel to it, one that's different from the Tolkienesque type of fantasy setting. In point of fact, the Blight is more related to the "weird fiction" methods of pulp novels than it is to Tolkien. That doesn't mean you'll automatically like it, of course, but I think it will dispel the idea that the setting is "modern." It's neither modern nor archaic, it's in a time frame that never existed in our world, which is why I'd put it in a category with the strange worlds of Michael Moorcock, the dreamlands of Lovecraft, and even to a degree with M.A.R. Barker's world of Tekumel. [Note: I'm going to add here someone else's impression quoted on Tenkar's Tavern, that the Blight is where Planescape meets Ravenloft. I think that's equally accurate as what I'm about to say below.]
But about the weird fantasy and sword & sorcery authors. As an example of what I mean, the Blight is a setting related to the way Michael Moorcock "built" Granbretan in the Hawkmoon novels. In structure, Granbretan is a possibly-post-apocalyptic setting with elements of Nazi Germany, baroque technology, and yet solidly rooted in fantasy even though there are flying vehicles and flamethrowers ... after all, the masked and armored warrior societies of Granbretan are opposed by people on giant flamingos with their own "flame lances." It's not "modern." because it's so divorced from realistic modernity that the modern elements don't create a modern feel. It's decoupled from reality, and it's decoupled from history. Interestingly, this ahistorical feel is offset in Granbretan with a major focus on clocks, and I find it interesting that Richard's Blight ALSO has a big focus on clocks. The Blight has modern elements that don't match up with history, putting it in an odd "between" space. That's also emphasized because the Blight is simultaneously threaded with an actual connection to a dimensional Between. These elements come together into something that Moorcock could have written, a blending of elements to create a place where the concepts of "modern" and "archaic" fail to function simply because as a whole they are so far outside the framework of anything, even though the elements themselves can all be identified as being similar to something from the real world.
So, what's the result here? Yes, the society in the Blight has very, very strong Victorian elements, roughly at the level of prominence with which Moorcock infused Granbretan with a Nazi-like feel. There's no question that the Victorian element will be felt. However, it's weirded up by a number of other things that eliminate the modern feel of the Victoriana, and make it into weird fiction rather than just "elves in Victorian London." There are no guns. The guards wear armor. The city's reality is infused with a nasty, creeping dimensional connection, and parts of the city even seem to intersect with distant places, receding again to their original lairs, like frustrated mold incursions. Jack the Ripper blends into a dark Alice-in-Wonderland, which blends into necromantic industry, which blends into the presence of monsters of all kinds in the city itself. It's a unique place, constructed from all kinds of elements, some identifiable from literature and history, others purely drawn from Richard's rather odd mind. It's still a completely valid question as to whether it's your cup of tea, but it's far more bizarre and alien than just elves in Victorian London.