Izzie as a character has more potential, her marriage for one, her surgical career came to a standstill, her frozen embryos.
Just because Katherine Heigl no longer wants to be part of Grey's Anatomy, doesn't mean Izzie should suffer, I am sure there are a lot of beautiful actresses out there that could bring new life to Izzie.
(They replaced an important character in the movies for example Rachel Weis in The Mummy and The Mummy Returns was replaced by Maria Bello in The Mummy: Tomb of the Dragon Emperor).
The actress should look similar to Izzie, she has to be tall, model like and ooze sex appeal.
Let's recast Izzie Stevens.