A short 4E adventure with pregenned characters was included on the Midnight Chronicles DVD. I was hoping that it would have special rules to reflect the Midnight world (i.e., no summoning, no divine power, limited magic items, limited healing, etc.). But it seemed no different to me than playing standard 4E with a party of only martial characters.
After thinking about it more, I think maybe a specific Midnight setting isn't necessary as long as you have the 3.5 books to draw the feel and fluff from. It seems like as long as you get the dire feel of Midnight down well, the mechanics in the setting aren't very important.