The title and lede from an AP article on CNN.com today:

Child care linked to later behavioral issues
WASHINGTON (AP) — The more time that children spent in child care, the more likely their sixth-grade teachers were to report problem behavior.

Meanwhile, buried in grafs 5 and 10:

The researchers said that the increase in vocabulary and problem behaviors was small, and that parenting quality was a much more important predictor of child development.

… The authors emphasized that the children’s behavior was within a normal range and that it would be impossible to go into a classroom, and with no additional information, pick out those who had been in child care.

Note that the increase in vocabulary was actually a positive. All in all, seems a bit like unnecessarily guilt-tripping a few million parents, eh?