Here's what groups concerned about civil rights and social justice are saying about Bush's new nominee.
From the Leadership Conference on Civil Rights :
<!--StartFragment -->... the nomination of Alito—affectionately called "Scalito" by conservatives—would fundamentally alter the balance of the Court, pushing it far to the right for generations to come!
Alito has demonstrated an extreme conservatism in the 15 years he has been a judge on the U.S. Court of Appeals for the Third Circuit (comprising Delaware, New Jersey, Pennsylvania, and the Virgin Islands). Alito's record exhibits a disturbing pattern of making it harder for victims of discrimination to prove their case. Particularly troubling are Alito's rulings on states' rights (i.e. restricting Congress' ability to protect civil rights and liberties), race and gender discrimination, and police misconduct.
People for the American Way released a preliminary but dense review  of Alito’s professional record, focusing on on the opinions, concurrences and dissents written by Alito himself. Their conclusions echo the concerns we're hearing from LCCR and others:
As the following summaries of his opinions reveal, the judicial philosophy of Samuel Alito is far to the right. In fact, he has been given the nickname “Scalito” by some who practice before him and liken him to U.S. Supreme Court Justice Antonin Scalia. He has demonstrated hostility toward the principles undergirding a woman’s constitutionally protected right to govern her own reproductive choices – most notably in the Third Circuit’s attempt to limit or overturn Roe v. Wade in the context of the Planned Parenthood v. Casey case. In addition, he has issued a number of troubling opinions that seek to undermine established civil rights law, especially in the areas of gender and race, and that seek to severely limit the federal government’s ability to protect its citizens. Alito claimed that the federal government could not apply the Family and Medical Leave Act to state employees, a decision effectively reversed by the Supreme Court, and even argued that Congress could not enact a ban on the possession of machine guns. It is clear that Alito’s confirmation would seriously jeopardize Americans’ rights.