As someone who doesn't celebrate Christmas, I can say, in my experience, everyone uses it as an excuse to blow off work, even if they show up. Service this week is awful, everywhere, and it is impossible to get anything done before New Years now.
However, there are a great number of "Joe Blows" who are involved in charges, not just the Big Wigs in the offices, and many of them are likely off a lot of days between now and Jan 4, as well, so it's not just one special rich guy making everybody wait.
Tis the season and all that.
JMOO
ETA: I also don't think it is a small factor that the budget re-starts in January, and the media will be "back to normal." Anything done this week would just go to continuance or sit on someone's desk anyway, so, IMO, it makes sense to wait. Why rush to prepare something that isn't going anywhere for a couple weeks? (Esp if the evidence isn't ready.)