Why not? Too sexy. Barbie must be a glossed-over, non-threatening blend of perfectly upholstered but strangely sexless.

With her unseemly posing for gentleman's magazines, Ms. Heard is developing a reputation as something of a strumpet. In this vein, the producers would go for someone pretty and pouting but - as they see it - a bit classier...

Depressingly likely alternative: Paris Hilton.