I'm pretty sure most of the things of MS's conference didn't leak.
It's definetly a lot of stuff when you consider it's a 90 minutes conference and games like Gears 4, Battlefield 1 and others will get live demos.
The Slim was definetly the big announcement of the ending part where they'll probably talk about their new direction and integration with Win10.
Btw talking about the Sony conference....god please....if Sony has to lose time on Watch Dogs 2, Titanfall 2 and COD Infinite Warfare because they got the marketing rights....plus the VR section....most of it will be a borefest for my tastes :/