Is there going to be a fifth gen in Pokemon

Yes, there is a Pokémon 5th Generation. There are lots of new Pokémon in the 5th Generation such as Zorua, Zoroark, Tepig, Pignite, Emboar, Zekrom, Reshiram, Kyurem, Victini, Oshawott, Dewott and Samurott.
The games of Pokémon Black and Pokémon White are currently out and there's gonna be 2 second games which are sequels of Pokémon Black and Pokémon White which will be called Pokémon Black 2 and Pokémon White 2 which have already released in Japan but will be released in the United States of America on October 7, 2012.