Actually, they announced TWO episodes - Metal Part 1 and Metal Part 2, set for September and December.
Of course, this follows yesterday’s announcement that DCUO is launching on the Nintendo Switch on August 6th.
A good year to be a DC-loving video-gamer. 
is this an online video game only?
Yeah, @Bwana, as @Biff said, it does require an internet connection, but you can do a lot all by yourself.
And even when you do have to group up for the bigger stories (no, you’re not taking Darkseid or the Anti-Monitor down alone), most of the community is pretty helpful. 
Welp, time to dust of my old Cyborg Superman style character. I loved DKM 
Do you still have to create your own character? I remember playing for a day or two and didn’t dig that I couldn’t play as my favorite heroes
Yes, the main part of the game still revolves around creating your own character and playing alongside the Iconic Characters of the DC Universe like Superman, Batman and Wonder Woman (or Lex Luthor, The Joker or Circe if that’s your style).
However, once you get a few levels in, you get access to Legends, which allows you to play AS the Iconics. You can play as Nightwing (or say, Bane) in Bludhaven, as Supergirl (or General Zod) in Smallville or as Green Lantern (or Atrocitus) in the Oan Sciencells. You can even play as these characters in PvP.
Lots of options, lots to do.