You want a plot line? Have your pick!
I tried to make sure that it includes opportunities for temporary characters in the game, and some meaty, independent stuff for each group. Don't forget to suggest your own desired plots in the comments if there's something you're interested in doing and want someone to take you up on.
Remember, these are all just suggestions, and meant for you to take and manipulate as you please! This post is a great place for thread hook-ups, too, so don't be shy about leaving a comment here.
( Sorry to journalists who didn't get a section, but Lockhart's with the Death Eaters and Jack Chambers is mine so I think I'm excused. )