The Summer Games 2017 will kickoff on August 8 and run until August 29. As part of the second annual summer games, Blizzard has made some updates to Lúcioball including a new Sydney map (matches will rotate between Sydney and Rio). Additionally, Lúcio's ultimate will not pull the ball towards the player anymore, but rather increase his speed and the speed of his "boop". Lastly, there will also no longer be the ability to "boop" opponent players.
Blizzard is also introducing a second competitive mode for Lúcioball which will place and rank players. So basically it's another chance to prove your dominance in the Summer Games 2017.
There will of course also be new Summer Games costumes which can be won through special loot boxes, or purchased. The Legendary Skins will cost 3,000 credits while Epic Skins will be priced at 750, with prices dropping for each lower tiered skin. However, Blizzard will also make last year's Summer Games skins available for purchase, with Legendary Skins starting at 1,000 credits. So if you missed out on some of the good sports skins from last year, here's your chance to try for them again.
So there you have it, more Summer Games and more Lúcioball. For me, it's mostly just my chance to try again for that Zarya skin I missed out on last year..
Check out our Overwatch Summer Games 2017 event hub page for even more info.