The United States women's national team has a 13-1 edge on Mexico in shots and holds a significant edge in possession. Despite that, they're actually not playing very well at all, as they have squandered golden opportunities while also taking a number of poor, ill-advised shots. They've only hit the target three times and they've only seriously challenged the goalkeeper once, when Shannon Boxx had a header saved. As a result, the game is tied 0-0 at halftime.
Amy Rodriguez was particularly poor in the first half, squandering a couple of clear-cut goal scoring opportunities with poor shots that missed the target. Megan Rapinoe's service from dead balls has been substandard, Amy LePeilbet has worked hard, but ultimately failed to provide great service from her new left back position, and the team as a whole has not done a good enough job of finding Heather O'Reilly and Abby Wambach in dangerous positions.
The United States were better than Mexico in the first half, but that has more to do with Mexico's relative lack of physical talent and conservative style of play than anything great that the USWNT has done to this point. Their play so far has not been up to World Cup standards, and they need to improve considerably with their opening game in Dresden just a couple of weeks away.