According to PowerRangers.com the new season title for Power Rangers Season 18 will be called Power Rangers: Samurai. On the PowerRangers.com website, they have a backstory posted about the 18th season.
A new generation of Power Rangers must master the mystical and ancient Samurai Symbols of Power which give them control over the elements of Fire, Water, Sky, Forest, and Earth. Under the guidance of their all-knowing mentor and the aid of their devoted animal Zords, they battle the dark forces of the Netherworld and a mysterious Warrior bent on destruction.
We also learned the real names for the Power Rangers.
Jayden - Red Samurai Ranger
Kevin - Blue Samurai Ranger
Mike - Green Samurai Ranger
Emily - Yellow Samurai Ranger
Mia - Pink Samurai Ranger
Takeru - Rangers Mentor
Xandred - Evil Master
Kevin - Blue Samurai Ranger
Mike - Green Samurai Ranger
Emily - Yellow Samurai Ranger
Mia - Pink Samurai Ranger
Takeru - Rangers Mentor
Xandred - Evil Master
Also, on the Power Ranger site they give you exclusive Samurai Ranger pictures with info on each Ranger.