Sir Alex will retire at the end of A season, could be this year, could be in five years, you will never know when untill THAT season ends because the last time he announced it we fell apart.
Of course no one knows for certain what Roman's plans were, but there's a reason the popular opinion was that he was hoping that Pep would join at the end of the season. When he sacked RDM, everyone knew Pep was halfway through his 1 year sabbatical and would be looking to join a club at the end of the season (allegedly, obviously it's happened sooner now). Mourinho had signed a 5 year contract 6 months previously, and had not fallen out with his Madrid senior players/fans yet... What does Roman do? He hires Benitez on temporary basis until the end of the season. Surely this points to him wanting Pep... If he wanted Mourinho, why wait for 6 months? He would just offer him a shedload of money, as it would come to that at the end of the season anyway...