Sonia Sotomayor is an activist judge. So were the magistrates of FDRs "New Deal." The fact that an American President sees an activist judge as his candidate of choice probably signals another "New Deal" era.
Judges are supposed to be "above it" all. Most of the time they are. This consensus formed thirty years or so later, in the 1960s and 1970s, when social change threatened to tear the country apart. Then there was a clear need for an independent judiciary to stand clear of the e.g. Nixon Executive Branch.
The one person that seemed to threaten this consensus was Clarence Thomas, who, like Sotomayor, was a minority, and one seen as out of the mainstream, although to the right. Judge Thomas has since been assimilated by the court, and is now very much part of it, although to the right of center. Perhaps Sotomayor will undergo a similar transformation, although to the left of center.
We do not need an activist judge. But we may need Sonia Sotomayor to remind us of why we don't need activist judges, a function performed "admirably" by the New Deal judges. If Sonia Sotomayor eventually propels the U.S. to a higher, colorblind judiciary, she may have performed a service after all.