"I really want to get around to doing it but I expect it won't happen"
That's my usual definition of Soon. Most people who say soon mean, "it won't happen but it's rude to say no". (Edit: of course, excepting mundane context like "when is dinner")
In the Blizzard world, I've come to learn Soon means "don't get your hopes up". I remember... Was it in TBC? Where I was playing my druid a lot. I was gonna take a break of WoW, but then the devs said, about new druid forms, that it'd be "soon" and I decided to keep playing until then, thinking in my naivity it'd be at most 2 months. Yeah, right.
In their defense, new druid forms did happen. Eventually. In a very distant point in the future. New models have been taking the same road. I almost got my hopes up for that one when they went Soon on us. Yeah, right...