It is definitely worrisome.
The limited data is showing that increased hive collapses are localized. We have to remember there are huge parts of North America where this is NO problem. The Dakotas and Canada hardly have these problems. Also, where hives are used in more hilly and mountainous areas are not experiencing these problems. These are clues to figuring it out as well.
Also, we have a tendency to look for one-explanation, one-cause. It is harder for us to accept some notion of multiple-cause as THE cause for CCD. Lots of hives dying? That’s lots of bees to study.