21st May 2013​
18:00 GMT​
13:00 EST​
10:00 PST​
On Tuesday May 21st, we’ll mark the beginning of a new generation of games, TV and entertainment. On that day, we’ll be holding a special press event on the Xbox campus and we invite you to join us via the live global stream that will be available on Xbox.com, Xbox LIVE and broadcast on Spike TV if you are in the US or Canada.
On that day, we’ll share our vision for Xbox, and give you a real taste of the future. Then, 19-days later at the Electronic Entertainment Expo (E3) in Los Angeles, we’ll continue the conversation and showcase our full lineup of blockbuster games.
We are thrilled to pull back the curtain and reveal what we’ve been working on.

Source: http://majornelson.com/2013/04/24/xboxreveal/

Major Nelson has also said he'll be posting updates about the event throughout the weeks leading up to the event. https://twitter.com/majornelson

So then, are you eager to see what Microsoft have in store for us? I wonder if the long wait for this reveal will pay off, or if they've improved their upcoming console to compete with the Playstation 4? All we can do is wait and see.