There seemed to be an abundance of solid information inside the post. I'm counting a couple of things he said they can reveal guidance on later: the replacement potions plus the trait/attribute system change.

Games change much, particularly when they are not in beta, i am not saying it's vaporware. Hell check out Guild Wars 2 http://www.guildwars2gold.org/ . they brusquely trashed, what, two previous attempts in the game because Blizzard didn't like where these were going? Nevertheless there have been major system hauls since they've started speaking about the overall game thorough.

That's how quality game developers do things, they play test the heck outside of their games in case a selected system isn't adequately meeting the developer's expectations they'll likely either change it scrap it are available program a fresh system that does. It's not something to worry about.