The most important aspect of this is keeping it consistent. Speaking of which... Android messed this up royally where they just changed their minds and changed

The most important aspect of this is keeping it consistent. Speaking of which... Android messed this up royally where they just changed their minds and changed all dialogs to the other way with (if I remember correctly, which I probably am not) Android 4.0 Ice Cream Sandwich. Drove me insane trying to relearn muscle memory to ok/cancel. Maybe they have documented their reasons for it? (couldn't find it)