Reasons why I think this is a fake list:
1. 50 achievements have historically been the number for vanilla DA games, and this list fills that out, meaning that in all likelihood, the list would be representative of the complete game, and thus not incomplete.
2. Historically, there were 'hidden' achievements in Dragon Age, ones that showed the various branching paths, be it templars or mages, elves or werewolves, paragon or renegade, and there are no branching achievements like it.
3. If multiplayer was created and available, I really doubt that only one achievement would be devoted to it.
4. The 'maker's breath' achievement for single-hit damage strikes me as a very odd name, and I would expect it to be more along the lines of 'big hitter' or 'lethal'
5. Given the...less than spectacular reputation of Dragon Age II , and the fact that a completely new engine is being used, I have doubts that Dragon Age II achievement icons are being used as placeholders, rather than a unique default icon, and I find it a little convenient that multiplayer got its own unique icon to make it visually distinguishable from the rest.
6. A lot of the story achievements are either reasonable guesses or already revealed through official channels, and I think Bioware has held back enough to still hold surprises either for later reveal or for the game proper.