At the moment, not much! It's a rare lull in the chess world, but it won't be for long. Other than Ding Liren (we'll have a separate post on his adventures shortly), the top players have been out of action for a little while. This will change in a few days.
First, the U.S. will have a super-strong event for its best players (except for Hikaru Nakamura, who was presumably invited and turned the invitation down so he could stream and prepare for the Candidates) in the 2022 American Cup. It starts April 20 (administratively, it starts on Monday, the 18th, but they don't play until Wednesday), and is an eight-player, double-elimination event with a 90'+30" time control unless one is in the elimination bracket, and in that case it's 25'+10". (Seems confusing, but I'm sure all will be clear once the event is underway.)
Anyway, it's a great field, with Levon Aronian (2785), Fabiano Caruana (2781), Wesley So (2778), Leinier Dominguez (2756), Sam Shankland (2709), Sam Sevian (2693), Jeffery Xiong (2685), and Ray Robson (2681). (The next Olympiad is looking tough for countries that aren't the U.S. - but then the Voldemorts Russians were favored every time for a decade or so without winning, so one never knows.)
Once that's over, a pair of Grand Chess Tour events will soon follow: a classical tournament in Bucharest and then a rapid & blitz contest in Warsaw. Magnus Carlsen won't be in either event, but the rest of the top ten (except for Anish Giri) will be participating in one or the other, or both, including Alireza Firouzja; top Americans Aronian, Caruana, So, and Dominguez; Candidates Ian Nepomniachtchi and Richard Rapport; former World Champion Viswanathan Anand; perennial superstar Maxime Vachier-Lagrave, and so on.
A week after that's finished, it's time for Norway Chess, and Carlsen and Giri - and many other great players - will be participating. Veselin Topalov hasn't been so active in recent years, even before COVID, but he'll be giving it a go.
Once that's over: the Candidates. Both Rapport and Teimour Radjabov are playing there straight after Norway Chess, which is an interesting decision to say the least. In fact, Rapport is playing in every one of the aforementioned events, except of course for the American Cup. Will he have any energy - and opening prep - left by the time he gets to the Candidates?