Having observed Sonia Sotomayor since I clerked on the Second Circuit during her first year on that court, I've generally taken a more skeptical stance on her nomination than my friend and colleague Walter Olson. I certainly agree with him on this point, though:
"It's not as if I think Obama's incapable of nominating someone who is more adventurous and more activist by nature."
Case in point: my old Civ-Pro professor, Harold Koh, whom the POTUS has selected to serve as top lawyer in the State Department (a nomination that is still awaiting a hearing before the full Senate). Dave Kopel writes about some of Koh's Second Amendment views here.