The way the 'Pre-Release' Lr3 tutorial will work is that the product in the store will have a 'pre-defined' number of zip files; probably around 40. Initially most of these zip files will be empty and simply place-holders. Over time as I complete each video segment, the zip files will be filled. Notice will be given of new files in three places: on this forum, on the What's New page and in a Table of Contents that will be placed in the last of the zip files. This way, a small download of the latest ToC will show whether you have the latest files or not. The Lr3 tutorial will initially be priced with a double discount: the first a discount for previous purchasers of the LR2 tutorial and the second a 'Pre-Publication' discount available until the product is completed. But yes, you will have to buy the whole thing, there will be no piecemeal purchase.