Stealing sermons?

Immature poets immitate. Mature poets steal.

- T. S. Eliot, "The Sacred Wood"

Every artist is a cannibal.
Every poet is a thief.
All kill their inspiration,
Then sing about their grief.

- Bono, The Fly

Do you think there is anything wrong with preaching a sermon that someone else wrote? What about preaching a famous historical sermon (perhaps giving a little context where necessary)? In both cases, I am assuming the preacher gives due credit.*
*Though even this concession makes me wonder how much preaching is about building a reputation.