Here a little bonus from my Nintendo Power
It won't be too complex
Punctuation is the most important part of this language
Oh my god yoshis talk like pokemons by repeating they name ...
but I believe this one is just coincidental and this way of speaking are not limited to Pokemon.
To name a few, John Malcovich ( Being John Malcovich ), Matt Damon ( Team america ), Timmy ( South Park ) or Gary ( Fallout3 ) all talk like that.