I hope you found the Stephenson sermon on St. Nicholas of some use. Sometime ago my partner here at Redeemer, Rev. Michael Frese, said: "When I hear really good preaching, it makes me want to preach." I'd never heard it put quite that way before, but I'd felt it. He is spot on. I think we need to spend some time cultivating good sources for this inspiration. Luther's and Walther's postils fall pretty flat for me. Pius Parsch and Patrick Henrty Reardon, neither of whom are Lutheran, do more for me in this regard. What do you read, besides the Bible itself, that makes you want to preach?
I spent November in serious study and analysis of Dr. Norman Nagel's published sermons. It made me want to preach. I am now waist deep in Franzmann. Here is a little Franzmann gem you may not have seen, since it is not included in the single collection of Franzmann sermons Ha! Ha! Among the Trumpets!. It is the sort of thing that makes me want to preach: Who Is a God Like Thee? by Martin Franzmann
As flat as Luther tends to be in the Postils, I do find the Genesis lectures and the late sermons from Volume 51, particularly On the Sum of the Christian Life (p. 259) Sermon in Castel Pleissenburg (p. 303), Baptism of Berthold Von Anhalt (p. 315) make me want to preach.