Now this is what I'm talking about!
Love these options. Circle of the Forged sounds very very different from anything I've ever heard of before with a Druid. Fascinating.
I'm curious how Mind domain will differ from Knowledge Domain (and Arcana, to some extent). Probably more Psionics-lite. Sounds a bit like the Divine Mind from Complete Psionic…
Dirge Singer is a big YES. As is Living Weapon!!!!!
And Maverick and Forge Adepts sound like great additions to the Artficer fold. Maverick sounds like it could even be a sort of Dr. Frankenstein/Dr. Jekyll/ mad scientist, delving into forbidden fields. I'm curious to see how Science and Arcane Magic will be further distinguished by this book.
And 40 pages of crunch!!!? I'm guessing that's mostly from the Monster portion of the book, but this is a huge expansion to the game.

Here's hoping we don't get these options in a different form from WotC down the road; I'd hope they'd at least respect Keith Baker's labour of love for his own setting, if they respect anything at all coming from the DM's Guild (we've definitely seen in UA some takes on concepts that appeared earlier in say, Xanathar's Lost Notes, and that was Guild Adepts!).
EDIT: Interesting afterthought - College of the Dirge Singer does, in fact, seem to tread on the same ground as a Xanathar's Lost Notes (and thus Guild Adept) subclass, the College of Mourning. Morgrave Miscellany carried over College of Keys from that book, as they both were Ruty books, but it didn't carry over College of Mourning, so at least we don't have two separate "Dirge" subclasses of Bard in Eberron books.