Was some discussion on another thread about the 15 or so elite teams that have overwhelmingly dominated NCs in the past 25 years or so. Seems to me that the playoff system is going to make it even significantly less likely for a true 'cinderella' to win a NC because team depth is going to absolutely RULE in 15 game seasons and the 'big boys' rule depth.
Just as likely as before for a Cinderella and maybe easier. Like others have said there is plenty of lay off time before playoffs considering the depth argument.
A Cinderella now has a chance to go undefeated in a weaker conference and potentially get in the final 4. They'd only need to win two big games. Previously they may have been left out of the championship.
Take Memphis for example: if they had beaten UCLA (finished 10th), OM (finished 17th), and Houston, they would maybe have an argument to be in the top 4 at 12-0 this season. They would have had to only beat two ranked teams, play a weak conference schedule, and then go to the playoffs. I'd just about guarantee you they wouldn't be top two though in the old system.
This is even more true if we go to 8 games.