The Barbie and Ken dolls that you see in Toy Story 3 are based on real-life figures released by Mattel in the 1980’s. Below are pictures of the toys and the commercials that were made to market the figures.
This is what Barbie looks like in Toy Story 3:
This is what Ken looks like in Toy Story 3:
This is just more evidence of the amount of research Pixar does during development of their films.