For me.
Year #1's. Medvedev in the ATP. I think he is just a bit more solid than Zverev or any of the new crop. But if Novak remains on top, it will not surprise me one bit. For the ladies, there are at least 5 players that can get there, so I will go with whom I want, not whom I think because I really have no clues: Kontaveit. I give her 10% chance of doing it, which is better than what I would give anybody else. I just can't see Barty going three years straight, and Naomi will not play a full calendar.
Slams: ATP: Medvedev, Novak and Zverev, with somebody maybe getting the fourth (Tsisipas at RG?). This, of course, hinges on Novak getting his vaccine because RG and W will simply not allow players to come without it. WTA: Naomi, Kontaveit, TOTAL SURPRISE 1, TOTAL SURPRISE 2. And by TS I mean somebody ranked outside the top 20, to repeat RG and USO last year.
Retirees: WTA: Serena, Stosur, Venus, and somebody in her early 30's. Kvitova perhaps. ATP: Roger, Feli, Anderson. Nadal at 25% if the feet and knees decide that it has been enough. Kyrgios will announce it via Tik Tok.
Out of the top 10: Badosa, Pliskova. Maybe Garbie. ATP: Berrettini, Ruud and Hurkacz.
Into the top 10: Gauff, Alcaraz. Other than that, I really could not even guess.
Into the 50: Mussetti. In the WTA, 25 players will go into the top 50, for the first time. The separation between the #100 (788 points) and the #50 (1215 pts) is minute.
WTA will not play in China. Maybe the top 10 will make a statement and say the YEC should remain in Guadalajara. The ATP, of course, will say nothing and remain a political eunuch.
Odd thing to happen: ratings for the WTA at the Slams will be better than for the ATP.
And yes, Covid will interrupt the season. This thing is so far from over...