So now that everything has been announced. Here's my thought as far as Champions are concerned in terms of what I like to play.
Taliyah: She's probably the one I am looking forward the most. I like her design, and he playstyle (Landmark based) is something new that I find intriguing. Probably the first deck I'll try. I'm not sure who I want to play her with yet.
Kindred: This is another that I find really interesting. I want to try it in an Undying type of deck.
Azir, Nasus, and Renekton: Mono Shurima with Sun Disc just for the big payoffs. Not really something I'd play on regular basis though.
Azir: Not sure exactly with what either, but I like his design. No Sun Disc though.
Sivir: I just like her level up ability. Probably means Leblanc as support in the deck to help level her.
Lissandra: I want a tough Nexus, and I like the Frozen Thralls. I am not so excited by the Watcher though, Pretty sure a game where you summoned 4 x 8 mana units is pretty much won most of the time already.
Jarvan IV: I really like his design, although I am generally not a fan of Demacia. I'm curious if when you attack if your rightmost unit is a Support unit and Jarvan IV appears on the right of it, does he get supported or will the Support effect be resolves before he hits the board.
Nasus and Renekton: I've never been a fan of Fearsome or Overwhelm decks so they'll most likely be last if at all.
Leblanc: No decks around her, she most likely will be in a Sivir deck though.
There's a few existing that are getting new cards that might be worth revisiting, we'll see.
Aphelios nerf is unlikely to do much. I've said before I don't think he's the problem exactly, The Moon Weapons are simply too versatile and too easy to cycle through. Being a bit easier to remove might help somewhat, but not by much. I've never really thought to myself...if only he had 1 health less that all would be fine. They either need to make the Moon Weapons 3 mana, or require 3 spells to cycle through them.
I can't wait for tomorrow.