It can't be said often enough that the PCA is not the PC(USA). The PCA is the small but growing conservative denomination with its headquarters in Atlanta, Georgia, whereas the PC(USA) is the large but shrinking liberal denomination with its headquarters in Louisville, Kentucky.
The principal debate within the PCA is whether Anglican Bishop N. T. Wright is correct in his claim that Martin Luther misunderstood the message of Galatians, and whether the time has come for Protestants to recover their roots and move back toward sacramentalism, a more formal liturgy, the infusion of Christ's righteousness, and a higher ecclesiology--in short, towards Rome. Within the PC(USA), though, the principal debate is over the nature and meaning of sexuality.
Both denominations hold their national meetings (called "general assemblies") near the beginning of the summer with the PCA meeting each year and the PC(USA) every other year. This was the year for the PC(USA) to meet and the news is about what you'd expect from a denomination whose policy paper on abortion calls the killing of some unborn children "an act of faithfulness before God."
By a solid majority, the assembly's commissioners gave presbyteries the freedom to call and ordain practicing sodomites as elders and pastors, and they also commended to their congregations a paper on the Trinity that promotes renaming Father, Son, and Holy Spirit "Mother, womb, and child."
On the other hand, the PCA--also by a sizable majority--voted to form a study committee called the Ad Interim Committee on Federal Vision, New Perspectives on Paul, Etc. The denomination's Stated Clerk, L. Roy Taylor, described the assembly's action as follows...
In an affirmative response to overtures from the Presbytery of the Blue Ridge and Rocky Mountain Presbytery, the assembly approved the formation of an Ad Interim Committee on Federal Vision, New Perspectives on Paul, Etc. Some of the issues involved are the nature of justification, the roles of faith and works, and baptismal efficacy. The Moderator is to appoint the seven-man committee to be funded by designated contributions to the AC. The Standing Judicial Commission announced that it has accepted a memorial from Central Carolina Presbytery concerning Louisiana Presbytery's investigation of one of its ministers on those theological issues. An SJC hearing on the memorial will be held October 19 at the Old Peachtree PCA in Duluth, Georgia (Greater Atlanta).
Anyhow, try to keep these two denominations straight. Again, the PCA is the small but growing conservative denomination with its headquarters in Atlanta, Georgia, whereas the PC(USA) is the large but shrinking liberal denomination with its headquarters in Louisville, Kentucky.