The pokemon company has mentioned that a new generation is being made. It should arrive later this year in Japan. The game is going to be on the ds.
source: http://kotaku.com/5459349/entirely-new-pokemon-series-coming-this-year
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.pokemon.co.jp/info/game/g100129_02.html&ei=ifdiS-iZF4_INafXkPcG&sa=X&oi=translate&ct=result&resnum=1&ved=0CAgQ7gEwAA&prev=/search%3Fq%3Dhttp://www.pokemon.co.jp/info/game/g100129_02.html%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26hs%3DAqs
source: http://kotaku.com/5459349/entirely-new-pokemon-series-coming-this-year
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.pokemon.co.jp/info/game/g100129_02.html&ei=ifdiS-iZF4_INafXkPcG&sa=X&oi=translate&ct=result&resnum=1&ved=0CAgQ7gEwAA&prev=/search%3Fq%3Dhttp://www.pokemon.co.jp/info/game/g100129_02.html%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26hs%3DAqs