Nevada senator Harry Reid announced he will not be running for re-election in 2016. He is about 75 or 76 now, so he's about done anyway.
I fully expect Governor Brian Sandoval to run for the job and get elected. The Democrats don't have anybody I can see who would beat him, provided, of course, he wants the job.
Sandoval has been a shitty governor, but that has never stopped anybody from seeking a higher office. After all, they are like school administrators: the worse they are, the better they do.