The cast of ABC's "Dancing With The Stars" Season 17 has been announced.

The 12 new celebrities who will begin learning choreography, dressing in costume and learning some difficult dance moves were announced on "Good Morning America" earlier today.

Some of the most notable celebrities that were introduced include "Jersey Shore" star Nicole 'Snooki' Polizzi, "King of Queens" actress Leah Remini, Bill Nye "The Science Guy," and "The Mary Tyler Moore Show" actress Valerie Harper.

"Glee" actress Amber Riley, "High School Musical" actor Corbin Bleu, TV personality Jack Osbourne and "Pretty Little Liars" actor Brant Daugherty will also be putting on their dancing shoes. Rounding out the cast is NFL star Keyshawn Johnson, "Saved by the Bell" actress Elizabeth Berkley Lauren, singer Christina Milian and Blue Collar comedian Bill Engvall.

Harper as a contestant on the show is probably the most notable, as the 74-year-old actress was diagnosed with brain cancer earlier this year.

"The brain scans that you get every two months are looking better and better and better," Harper said on "GMA." "My doctors and neurologists...they are just delighted that I'm moving in the right direction. As my husband said, 'Let's just buy time, Val.'"

"DWTS" hosts Tom Bergeron and Brooke Burke-Charvet made the highly-anticipated announcement on "GMA" live, while also announcing who the celebrities' pro-dancer counterparts would be for the season. Returning dancers include Season 16 champion Derek Hough and other veterans including Cheryl Burke, Karina Smirnoff, Tony Dovolani, Mark Ballas and Val Chmerkovskiy.

Hough won the coveted mirror ball trophy last season with country singer and "American Idol" alum Kellie Pickler. He and Pickler's win last season marks the fourth time Hough has won the reality dancing competition.

Season 17 of "DWTS" marks the first season that the show will be combined into a two-hour program on Monday nights, with the performance and results show being held during the same telecast. The couple that receives the lowest judges scores combined with public votes from the previous week's performance will be eliminated. The new season launches with a two-hour premiere on Sept. 16.