Saban created them
A Japanese person within Toei created the Super Sentai series which is where Power Rangers originated from however Haim Saban is the one who bought the rights to the Sentai program in order to create an American show using the Japanese footage that was provided by Toei. Haim Saban enlisted the help of Tony Oliver in order to create the Mighty Morphin Power Rangers series.
Saban created Mighty Morphin Power Rangers, Mighty Morphin Alien Rangers, Power Rangers Zeo, Turbo, In Space, Lost Galaxy, Lightspeed Rescue, Time Force, Samurai, Super Samurai and Megaforce.
Haim Saban was the owner of Saban Entertainment which was responsible for bringing various shows over to the United States of America such as Power Rangers and Digimon. Haim Saban was instrumental in creating the Power Rangers series into making it a successful series however it was eventually sold to Disney as part of the Fox Family Worldwide sale but Haim Saban's Saban Capital Group had later re-acquired Power Rangers along with Beetleborgs, VR Troopers, Masked Rider and Teenage Mutant Ninja Turtles: The Next Mutation from Disney.
The reason why Power Rangers is no longer airing on ABC is because Disney sold the series back to Haim Saban, the original creator of Power Rangers and as part of the sale Disney had to stop all airings of the show worldwide as of September 2011.
Haim Saban of 'Saban Entertainment' created the original "Mighty Morphin' Power Rangers" in the 90s. The program was later produced by Disney's BVS Entertainment and currently (as of the Spring of 2010) by SCG Power Rangers LLC.
Disney had aired Power Rangers RPM throughout 2009 on the ABC Kids block however because of Haim Saban's Saban Capital Group buying back Power Rangers, Disney no longer has the rights to air Power Rangers on any of its channels.
No, the Elephant Princess was created by Jonathan M. Shiff who controls and owns an Australian production company while Haim Saban the owner of Saban Brands and Saban Capital Group is the man that owns Power Rangers and therefore was responsible for creating Power Rangers from Mighty Morphin Power Rangers through and including Power Rangers Time Force and then from Power Rangers Samurai to all upcoming seasons. Disney was responsible for the production of Power Rangers Wild Force until and including Power Rangers RPM.
Saban entertainment in the US, Supersenti in Japan.
Power Rangers was creater by Haim Saban.
Yes, Goseiger is currently being adapted as Power Rangers Megaforce.
It has not been confirmed but saban (read the answer for is power rangers ending to find out why saban own it again) are planning to make a movie