According to Scalabrine on his Sirius show this morning, around the trade deadline, Ainge went to ownership and told them he was probably going to step down. He said Wyc almost immediately went to Stevens and asked him about taking over for Ainge. It wasn't until that conversation that Stevens even thought about it, but apparently it became a voice in his head and the more he thought about it the more he wanted to do it. Stevens apparently didn't see a single one of his high school sons basketball games this year and that irked at him and Stevens believes the President job will provide him less travel and a bit more flexibility so he can be a better father. Scal also said that this had nothing to do with money from the C's end. That they love Stevens mind and think he will excel in this role. Scal also thought Stevens would be in the job for over a decade (unless he just isn't any good, which he didn't think would happen). Stevens is not just taking this as a stop gap and the C's weren't offering it to him as some sort of stop gap. Everyone legitimately thinks this is a good idea and it has been in the works for months. Scal also said Ainge was still going to be around for a couple of years and help out when asked or needed, including things like the pre-draft workouts.
I have no idea how tuned in Scal actually is, but it was a fascinating listen.
Scal also said that everyone, including the players, really respect and like Kara Lawson, so she will definitely be on the short list if she is interested.