The extent of changes (from the books) implied by the teaser and the Winespring clip are pretty much exactly what I would have expected.   It's pretty clear that the first episode is going to encompass the equivalent of the first 10-12 chapters of the first book. That's a pretty mammoth task, and a lot of decisions regarding minor plot deviations will have been driven not solely by how difficult it is to show something rather than tell it, but also how much time it would take both to "