A roundup of the leadership changes in the 111th Congress, such as I could put together:
With Democrats expanding their majorities in the House and Senate during the 2008 congressional elections, members of both parties sought to redefine the leadership structure within their respective caucuses. Some of the shuffling was predictable, while political calculation entered into consideration into other leadership campaigns. In addition, freshman members of the House and Senate were forced to take sides in their first actions in Congress, even though they have not been taken office.
H/T to John for the post title.