I got sick of looking at the default SMF theme, so I made a quick remake of my New Terra theme we had on the old IPB forums. This one is based on another theme called
DarkModern.
If your theme didn't switch over, go to Profile->Account Settings->Modify Profile->Look and Layout, click the "change" link next to "Current Theme", and select it (it's at the bottom of the list).
If you find any issues or have suggestions, let me know.