Nickelodeon announced a roster of more than 400 new episodes of animation, live-action and preschool programming, as well as a new ’90s programming block on TeenNick, at yesterday’s annual upfront event held in New York City.

The network will introduce 450 episodes of new animation programming over the next three years. The roster includes returning series like SpongeBob SquarePants, The Penguins of Madagascar, Fanboy and Chum Chum, T.U.F.F. Puppy, and the brand-new ones including The Last Airbender: Legend of Korra (a spinoff of Avatar: The Last Airbender), Kung Fu Panda: Legends of Awesomeness, and the Italian import Winx Club. Included in the lineup is the new CG-animated Teenage Mutant Ninja Turtles, which is currently in production at the Nick Animation Studios and is slated for release in 2012.

Almost half of this animated content is headed to a revamped Saturday-morning block. Starting this spring, the morning lineup, which currently delivers 3.2 million total viewers each week, will debut a new look and never-before-seen content, as well as original animated shorts, animated music mash-ups and celebrity guests.

On the live-action front, the network will produce more than 100 new episodes of its live-action series, spearheaded by a new original primetime TV movie event iParty with Victorious, which unites the casts of iCarly and Victorious this June. Additionally, the network will roll out new episodes of iCarly, Victorious, Big Time Rush, True Jackson, VP, House of Anubis and Nick News with Linda Ellerbee. The season will also feature new episodes of new Nick series debuting later this year, which include Supah Ninjasand Bucket & Skinner’s Epic Adventures.

The network has also ordered 125 new episodes of its preschool series, which include Bubble Guppies, Team Umizoomi, The Fresh Beat Band, as well as new episodes of Dora the Explorer. New seasons of Yo Gabba Gabba!, Max & Ruby and Olivia will also be a part of the preschool lineup. Additionally, Nickelodeon, in conjunction with media content company Chorion and publisher Frederick Warne & Co., is in production on 26 episodes of the animated preschool series The Tales of Peter Rabbit.

TeenNick, meanwhile, will receive a new nighttime programming block in Q4 called The ’90s Are All That! The block will feature a rotating selection of live-action and animated shows from Nickelodeon’s 1990s library. The shows include All That, Clarissa Explains it All, The Adventures of Pete & Pete, Rocket Power, Salute Your Shorts, The Amanda Show and Kenan & Kel. TeenNick’s audience will have the opportunity to influence the block’s lineup by requesting shows via social media sites set up by the network, including a dedicated Facebook fan site.