If this is true, then probably the new type would have something to do with the new pokémon formes. And if that would be the case I can picture some mutant pokémon. And Cyborgs too. I don't know if I like this.
I've read that rumor before, and it's what gave me the impression that Gen VI will not come out until 2014, so we're sticking with Gen V for 4 years much like the past two gens (III and IV).