Yea, the last three D's I've been to have been silent on the issue. At each, when making my initial contact with ground, I've stated direct to destination (and usually asked for them to arrange a hand-off with flight following). After cleared to takeoff, at all three D's, there was no mention of runway heading, etc.. I contacted the first after a couple of miles and well above pattern altitude (but inside the D), and asked if I was free to resume, and she said yes, in a tone of, "Why are you asking me this?"
The next two, I just kind of guessed and made my turn as one would when departing the pattern at a pilot controlled field.
Good answers, thanks all.