Avent studies the GDP revision:
Not only was growth revised downward. In addition, what growth occurred was more dependent on transitory factors and less dependent on the underlying economic fundamentals than earlier seemed to be the case.
This isn't a complete travesty of a GDP revision, but it does suggest that recovery is weaker and less well established than was previously believed. Which makes sense, against the rest of the statistical landscape, including weak job growth and a surprisingly market vulnerability to European crisis.