What exactly does "Ancestry.com’s commitment to grow the collection weekly" mean? What rate of growth is Ancestry committing to? And for how long?
I recall another, similar committment (made by whoever was their owner at the time) of 3 volumes weekly to be added to the Genealogy Library, which they more-or-less kept to until it suited their purposes to abrogate their so-called committment without notice or explanation.
In short, such committments aren't worth the paper they're printed on. (Oh, right! What paper?)