Shane Kirshenblatt of Freefall Comics has kindly updated us on the status of this book and why the first solicitation was cancelled.
I just thought I'd write here to mention that Dorothy Gale: Journey to Oz Book One can be ordered directly from the publisher, as there are still quite a few available.
I would also like to clear up the cancellation issue regarding book two:
It was originally intended to be a 36 page installment, however, the story demanded more pages and time to complete it. Although Previews doesn't say so, the book will actually a 64-pager, which would explain the higher price-point.