You couldn't have a harder act to follow than Sir Alex Ferguson and I can't help wondering what will happen over the next few months at United.
Not only do they have a hugely-important appointment to make but they appear to be losing Paul Scholes from the playing staff and, if you believe what you read, Wayne Rooney wants to leave too.
This is a pivotal moment for one of the greatest clubs in the world.
David Moyes is cut from the same cloth as Fergie and for my money is clearly the best man for the job. He's tough, he doesn't tolerate fools gladly and he works his socks off.
People will ask 'what has he won?' but I think what he has achieved at Everton season after season after season is absolutely astonishing.
Others will say that he hasn't worked with 'big name' players. Well, they don't come much bigger than Rooney and he gave him his chance when he was a kid and now he works with a team of international players.
He's got passion, he's got drive and he's clearly a good tactician, otherwise he wouldn't be where he is now and he wouldn't have got Everton to where they are on a limited budget.
You have to be a certain type of character to manage United and Moyes, having learnt his trade at Preston, is one of the few to fit the bill.
I don't know him well - I've met him a few times - but like Fergie under that vaguely-scary exterior lurks a warm, witty, generous person.
Fergie will, of course, be somewhere in the background but he's a wise old thing and he'll know that his role is now to be in the background and not on the shoulder of the new boss.
I'm sure he'll be there for advice when asked, but I expect he will wait to be asked.
Moyes has worked miracles over the years at Everton and will leave a huge void if he does go. Given the circumstances, you wonder what impact Moyes' departure might have and what the future holds for players like Marouane Fellaini.
If I was an Everton fan, I would be concerned because they know the club hasn't got shed-loads of money to spend; they know how good a job Moyes has done at getting the best out of players bought for relatively limited amounts and the stability he has brought to the club.
Whoever comes in has huge shoes to fill. My personal view is that Roberto Martinez - a bit like Moyes in a way, but playing a different brand of football - has done phenomenally well at keeping Wigan afloat on a limited budget.
If there is any manager around who deserves his chance at a bigger club, it is certainly Martinez.
Everton fans will know what they're getting; they'll know their side will play a wonderful, attacking, patient style of football that will be great to watch.
We could end up in the situation where the two Merseyside giants are both managed by former Swansea bosses. I'm sure you could have got a million-to-one against that a few years ago!
JEFF'S GEM OF THE WEEK
It has to be Leicester's 3-2 away victory over Nottingham Forest. The last day of the regular Championship season was one of the best days I can ever remember! It wasn't far away from rivalling last season's finish to the Premier League. WATCH THE STORY OF SOCCER SATURDAY HERE.
The permutations at the foot of the table were incredible and any one of seven teams could have filled that third-from-bottom spot before Peterborough slipped into it. There was a surreal finish to the game between Barnsley and Huddersfield, where the keeper kept the ball for about two minutes with no-one going near him while the managers hugged each other on the touchline.
Events at the other end of the table were no less fascinating. A lot of my followers on Twitter will point out that I wrote Leicester off a few weeks ago, but they needed a couple of things to happen at the weekend and they got them both - Bolton didn't win and they beat Forest to grab that sixth spot.
Leicester were absolutely exhilarating in the first half and after being pegged back at 2-2, they had the strength of character to finish strongly. Earlier in the season, I thought Leicester had a fantastic chance of automatic promotion but for some reason things went slightly wrong. But Nigel Pearson is like Fergie and Moyes (without the accent) in the sense that he is hewn from granite and has great strength of character. I was pleased for him that his side came back and made the play-offs. It would not surprise me one jot if they now go on and win the play-offs.