This is what I believe Microsoft will show at their conference at E3:

Hololens, Windows 10, software anouncements - 20 minutes;

Halo 5 single player trailer - 5-8 minutes;

Gears of War 4 CGI trailer - 1-2 minutes;

Gears of War Remastered announcement + trailer - 2-3 minutes;

Forza 6 gameplay reveal trailer - 5 minutes;

Rise of the Tomb Raider gameplay reveal trailer 5-8 minutes;

Fable Legend gameplay trailer - 4-5 minutes;

Crackdown gameplay reveal trailer - 4-5 minutes;

New controller announcement - 1 minute;

New Rare game announcement (CGI or without trailer) - 2-3 minutes;

Scalebound reveal trailer - 5-7 minutes;

Killer Instinct Season 3 annoucement - 2 minutes:

Trailers of timed/true exclusive indies - 3-4 minutes

The Division new gameplay trailer - 5-6 minutes;

The other 15-20 minutes will be about other third party games, announcements of games/software updates we don't know know yet.

And no, I don't think we will see Quantum Break, I believe they are going to show it at Gamescom like last year.

What are your opinions about it? Please share your thoughts. 

Oh, and please tell me if I forgot something very obvious!

Wasn't Scalebound already revealed? Do they need a new controller?

No cod?

Good list though.

i miss some call of duty
still not sure about the Marketing. i expect it to be "neither exclusive on ps4 or xb1"

Not the gameplay, that's why I wrote gameplay reveal trailer :)

And I wrote about the controller because of the last rumors.

you forgot the 15 min cod demo nobody wants to see

About Call of Duty, since I don't know who got the marketing rights (maybe Sony), it can be put in the final 15-20 minutes of third party/other stuff we don't know about.

As I said before, I left 15-20 minutes of third party stuff and surprise announcements.

gameplay 

I think people are already expecting way too much of Microsoft's E3.

Don't get me wrong, I want all the weird and wonderful predictions to come true, but realistically I think we'll get two or three new announcements comprising new and old IP.