Most likely chance of 4.0 will be around this time next year post all the fan fests I'd say. I don't recall them ever mentioning 1 year expansion but I do recall mentioning that 2 years is a bit to long to something like 1.5 years being just right.

I like the time that heavensward took to get out - felt just about right. Had time to catch up on old stuff that I didn't manage and other such stuff.