We also have situations developing in Indiana, Kentucky and Louisiana.
-In Indiana, Governor Mike Pence, has yet to decide if he is going to run for President in 2016. Indiana law prohibits a candidate from running for two offices at the same time. Therefore, if he runs for President: we will have an open race for Governor in 2016. He could, however, try a run for President and if he doesn't get any early traction, still drop out of that race before the filing deadline for the Indiana Gubernatorial.
-In Louisiana, we have a 2015 Gubernatorial election to replace Bobby Jindal. The most likely GOP candidate will be Louisiana's Senior Senator David Vitter who's seat will be up in 2016. If elected Governor in 2015, he would be able to appoint an interim replacement in early 2016 and set up a possible run for a full term for that appointee that fall. Or that appointee could sit out running for the full term and leave a completely open race. One of the more appealing Democratic candidates would be now Former Senator Mary Landrieu. Or, possibly, Mitch Landrieu the current Mayor of New Orleans. Though he may pass on that, or run for Governor in 2015.
-Kentucky brings a situation similar to that in Indiana. Rand Paul cannot run for Senate and President at the same time which may leave an open Senate seat for 2016. There are a variety of options here depending on who ends up running in 2015 for Governor.