First off, I apologize for the hiatus. I've had a lot going on in life and time to work on TA/TG was unavailable to me. Things have been corrected now (or so I think) and I should have a little bit more time on my hands.
That said, the idea at this point is to split TA/TG into 3 books. The reasoning for this is that I can release the first book much sooner. It will still be a decent-sized book (easily over 100 pages, possibly over 200). But the rest of the "first book" that I'm working on appears to also be in the 200 page range. So rather than release 2 books (with a delay of 3+ months on the first release) with one book in the 500 page range, I'm planning to release 3 books. The difference between pricing a 500 page book and a 150-200 page book is sizable. So this will allow me to keep the cost down, which is important to me.
The first book will be a sort of "Player's Handbook". It will contain all the classes (except the Theorist who will still appear in the Transylvanian Grimoire. It will also contain all the rules addendum needed to run TA/TG at the table, as well as a 0-Level funnel adventure.
The second book will be a "Judge's Guide". It will contain the hexmap of Transylvania, new monsters and lots of charts and setting information. I may be able to put together a higher level adventure as well. Or maybe commission one.
The third book will be the "Spell Book". This will contain the Theorist class as well as all the spell charts for TA/TG. A few monsters and adversaries too.
There's more that will make it into each book but I think this is a logical split. It allows people who just want the classes and rule tweaks to buy only one book. Or those who just want the spellcasting systems to buy only one book. And it will keep pretty much all of the GM material in one book as well.
I'm also considering placing all three books under the "Transylvanian Grimoire" umbrella. Meaning they will all three be called "Transylvanian Grimoire" and separated by volume.