User blog comment:Kacj321/The Elder Scrolls V: Skyrim Leaked/@comment-3437860-20111103005851/@comment-3437860-20111104142417

Well, F3 and FNV had about 6-7GB on the old engine, and judging from the screen shots the new textures much more detailed. It just doesn't seem to me that the size scaled properly with the quality, which makes me fear maybe the size of the game was scaled down. I remember back when DA2 size came out everybody was wary, but BW assured us that they just had used a better compression. That turned out to be a big fat lie, so now I'm always leery of smaller-than-expected file sizes. I really hope I'm wrong though and they indeed just used a better compression.