If I were to speculate....

Maybe they ll show:

Demon Souls (rumored) or Bloodbourne 2 (maybe?)
new Raket & Clank game (its 4-5 years since last one)
Silent Hill Reboot (exclusive)
GodFall (exclusive)
Grand Turisomo 7
Last of Us part 2 - Multiplayer stand alone game.
new Resident Evil
Street Fighter 6 (exclusive?)
Call of Duty - Cold War (marketing deal)
HZD2

+ 30-40 others from 3'rd party.

Not showing (will be saved for lateron):
Spiderman 2, God of War 2, Days Gone 2, new Uncharted game..

Also (BC):
Since theyre talking about PS4 backwards compatability, and possibily 4000+ games from its (ps4's) library running in BC.
It would be good to show that, even if its a short demo.
Again if they show the same with a PS1, PS2, PS3 disc as well... and market it as the "ultimate" playstation system.

I wouldn't expect that many games to be shown as the event seems to be about an hour long and there surely will be some talk about the hardware/UI design. My guess is about ~20 in total, hopefully with a focus on gameplay.

RUMOR (From Resetera)

- final design doesn't look like anything that has been leaked before
- PS5 has one unique detail, nobody talked about it because Sony most likely can track down the leaker if it actually leaks
- Sony didn't unveil all the secrets of PS5, they should announce at least one software feature - "it was briefly talked about in Western press but nobody paid enough attention"
- design-wise PS5 doesn't look like Xbox Series X at all nor does it look like a smart speaker. It's a traditional console: it's a flat, square, symmetrical box with rounded edges
- at the same time PS5 is "very fat", almost twice as fat as PS4 Pro

Sony will probably use the same strategy used for the PS4 which is to show/tease games that will be released only 3-5 years down the road. This will secure sales as people will be already hyped for what is coming down the road, even if this road is far away.

They changed strategy, which is why there has been no Sony 1st party AAA game announcement since Ghost of Tsushima in late 2017. The Sony games at the show are pretty sure to be launch and launch window games.

3rd parties (esp Square, Bethesda) ofcourse might still present games that are quite far from release.

Please show actual gameplay, not cinematic trailers, I don't care what games they are, just show the actual gameplay. And now I'm just be greedy but show me the console.

I agree, real gameplay and console

Nah, they won't. On every PS console reveal they've shown a lot of gameplay and some tech demo's on the side.

Really curious to see if Quantic Dream's has anything to show this time round.

I think you'll be getting what you want here.

It is June, so i guess the countdown for the launch is less than 5 months.