Based on initial media speculation involving both Roberts and Miers, there is reason to believe that both will be more supportive of gay rights under the 14th Amendment. Roberts assisted with efforts to get Colorado's state Amendment that denied equal protection to gays and lesbians. Miers, according to news reports, supported civil rights based on sexuality when she ran for city council years ago.
If this is true, it could well mark an historic move on gay rights, one the Court has already been trending towards--the protecting of gays and lesbians in a manner similar to the protections it provides against discriminations on the basis of race and sex. Both Rehnquist and O'Connor were in the majority of the notorious Bowers v. Hardwick which allowed a state to criminalize sodomy. Rehnquist was in the minority on Romer v. Evans, as he was on Lawrence v. Kansas. O'Connor was in the majority on Romer (which overturned the Colorado amendment) and concurred in Lawrence, arguing a bit twistedly that the substantive due process questions in Bowers were appropriate, whereas Lawrence involved Equal Protection.
If these judges are more sympathetic to the civil rights claims of gay and lesbian Americans, we would have only two judges left who were not in the majority of Lawrence and Romer. It might well mean that we would continue a shift that began in Romer--that gays and lesbians would receive hightened protection under the 14th Amendment and place greater scrutiny on government efforts to deny basic rights such as marriage and military service. It could also very well impact current Title VII law under the Civil Rights Act. Currently, discrimination in the workplace against gays and lesbians is not prohibited by the law. A change in 14th Amendment jurisprudence could well impact this critical workplace statute as well.