And it's coming with lots of new features, a completely new UI, and... a new name (previously it was known as Expression Interactive Designer)!
You may find more details on the Expression Team Blog.
But wait, there is more! A new CTP of Expression Design is available and... the final version of Expression Web! Also, a new member of the Expression family (Expression Studio) was announced today: Expression Media!
And... don't forget to check out the new Expression website for more details!