Alexander Bilus, a lawyer for the plaintiffs, had initially argued that without Corbett in the case he would have to subpoena individual state departments for documents on estate taxes, health care, and other issues on which state law provides different benefits to heterosexual married couples.
Pellegrini is the same judge who in September ordered Montgomery County Register of Wills D. Bruce Hanes to stop issuing marriage licenses to same-sex couples.
Lawyers for Corbett, Kane and the plaintiffs agreed that individual department heads, not the governor, would be "on the firing line" if they refused to comply with a ruling for or against Pennsylvania's ban on same-sex marriage.
That law, passed by the General Assembly in 1996, defines marriage as being between one man and one woman, and does not recognize same-sex unions performed in other states.
In Montgomery County in July, Hanes began issuing licenses in spite of that law, and dozens of couples married. Pellegrini's ruling against Hanes in September - which is currently under appeal before the state Supreme Court - did not specify whether those marriages were valid, prompting the couples to file suit.
Pellegrini said from the bench Thursday that he hopes this case will move swiftly.
"This should not be an issue of a vast amount of fact-finding," he said, noting that there are several similar cases currently playing out in Pennsylvania, and hundreds of others nationwide. "The arguments at this point are pretty much well-developed."
Bilus said he was happy with the result Thursday but might still consider adding Secretary of Revenue Dan Meuser or other officials as defendants. The Health Department is the primary defendant because it collects and enforces marriage licenses.