[Updated at 7:04 p.m. ET] The U.S. Supreme Court's announcement Friday that it will soon tackle the contentious issue of same-sex marriage is "a major event in American history, not just in Supreme Court history," CNN senior legal analyst Jeffrey Toobin said.

"The Supreme Court is not just going to decide whether the Defense of Marriage Act is constitutional, they are also going to decide whether Proposition 8 in California - whether the ban on same-sex marriage there is unconstitutional, and that could affect all 50 states," Toobin said.

The court says it will hear two appeals: one involving the federal Defense of Marriage Act or DOMA, which denies federal benefits to same-sex couples legally married in their own state; and one involving a challenge to California's Proposition 8, a voter-approved referendum that took away the right of same sex-marriage that previously had been approved by the state's courts. Read more about these cases.

Oral arguments in the high court appeal will likely be held in March, with a ruling by late June.

Here's some of what's being said about Friday afternoon's announcement:

Edith Windsor, who had a 42-year partnership with Thea Clara Spyer and is behind the DOMA case, told the Guardian's Adam Gabbat that she is "delirious with joy."

"I think it's wonderful," Windsor, 83, of New York, told the UK publication. "I think it's the beginning of justice like I imagined in fourth-grade civics. I'm thrilled at how it's gone."

In October, the 2nd U.S. Circuit Court of Appeals found, in Windsor's favor, that DOMA violates the Constitution's equal protection clause and thus she shouldn't have had to pay an inheritance tax after her partner's death.

Some opponents of same-sex marriage also welcomed the high court's intervention. The National Organization for Marriage, a group that helped lead the effort to pass Proposition 8 in California, said it was confident of prevailing.

In February, a federal appeals court in San Francisco ruled the measure unconstitutional.

"We believe (the Supreme Court's decision to take the case) is a strong signal that the court will reverse the lower courts and uphold Proposition 8," said John Eastman, chairman of the National Organization for Marriage. "That is the right outcome based on the law and based on the principle that voters hold the ultimate power over basic policy judgments and their decisions are entitled to respect."

Salvatore Cordileone, archbishop of San Francisco and the chairman of the U.S. Conference of Catholic Bishops' marriage defense subcommittee, said the high court's decision to consider the cases "is a significant moment for our nation."

"I pray the Court will affirm the fact that the institution of marriage, which is as old as humanity and written in our very nature, is the union of one man and one woman," Cordileone said in a statement from the conference. "Marriage is the foundation of a just society, as it protects the most vulnerable among us, children.

"It is the only institution that unites children with their mothers and fathers together. We pray for the court, that its deliberations may be guided by truth and justice so as to uphold marriage's true meaning and purpose."

More reaction from politicians, organizations and others:

In '86, Justice Powell, swing vote, told his law clerk he had never met a gay person. Times have changed. #scotus #ssm —

Jeffrey Toobin (@JeffreyToobin) December 07, 2012

Former New Mexico Gov. Gary Johnson:

SCOTUS to rule on #DOMA and Prop 8. Here's hoping they confirm that #gaymarriage is a constitutional right. Long overdue! #equality —

Gov. Gary Johnson (@GovGaryJohnson) December 07, 2012

U.S. Sen. Kirsten Gillibrand, D-N.Y.:

V plsd #SCOTUS will review constitutionality of #DOMA & #Prop8! Congress must still act & pass Respect For Marriage Act repealdoma.com —

Kirsten Gillibrand (@SenGillibrand) December 07, 2012

California Lt. Gov. Gavin Newsom:

Supreme Court here we come. SCOTUS to hear #Prop8 case. Love will triumph over fear! —

Gavin Newsom (@GavinNewsom) December 07, 2012

Justin Mikita, co-founder of TieTheKnot.org, which advocates "for the civil rights of gay and lesbian Americans":

Historic that SCOTUS will be hearing cases on Same Sex Marriage for the first time. This IS good news! —

Justin Mikita (@JustinMikita) December 07, 2012

Jessie Tyler Ferguson, another TieTheKnot.org co-founder and Mikita's finance:

Marriage Equality has finally made its way to the Supreme Court AND I'm on my way to @JimmyFallon to talk about @TieTheKnotOrg! What a day! —

Jesse Tyler Ferguson (@jessetyler) December 07, 2012

House Minority Leader Nancy Pelosi:

I'm confident Supreme Court will discard DOMA and Prop 8 into the dustbin of history. Let's get this over with and on to the future! —

Nancy Pelosi (@NancyPelosi) December 07, 2012

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