I argued here that the President should be seeking in his next nominee to the Supreme Court, someone with judicial experience. While he rejected my advice as to the specific jurist - I recommended Janice Rogers Brown - he certainly chose someone with a clear and distinguised record as a judge.
Chief Justice Roberts has experience mostly of the executive branch, and I fear he will not be as tough on issues of federalism and private property as Rehnquist and O'Connor were. But it seems as though Clarence Thomas will have at least one ally on these issues.
The Wall Street Journal suggests that Alito has been ahead of the Supreme Court on both these issues.
I still fear, for reasons previously stated that until Stevens or Ginsburg is replaced the Supreme Court will take a more left-wing position than over the past few years, but Alito is not only far ahead of Miers, but probably more reliable than Roberts.