The company is set for an epic showdown with Sony at Christmas time, with the Xbox One set to hit 21 countries at a price of $US499 ($527), although it'll likely be significantly more expensive in Australia.
UPDATE: EB Games has confirmed Xbox One will launch in Australia at a price of $599.
Sony is yet to reveal pricing or availability details of its new PS4.
Having faced a barrage of criticism over the new console's need to be 'constantly online' and its lack of ability to play used games for free, Microsoft returned fire with a series of flashy announcements.
"We have more titles in development today than at any other time in the history of Xbox," said Phil Spencer, head of Microsoft Studios.
Spencer told attendees the company had opened five new Microsoft studios in preparation for the console launch, and was "investing more than ever in games" including new franchises and "classics you've asked for".
Other exclusives headed to the new console include an open-world adventure game from Insomniac called Sunset Overdrive, game-building title Project Spark, Crimson Dragon, a spiritual successor to the much-loved Panzer Dragoon series.
At the begnning of its presentation Microsoft actually started off with Xbox 360 news, announcing a new, slimmer version of the console that went on sale today.
Microsoft executive Yusuf Mehdi told the crowd that the company wouldn't abandon its ageing console, and said hundreds of games will still be coming to the Xbox 360.
He also said that current Xbox Live Gold memberships will carry over to Xbox One, and starting on July 1 members will get two free game downloads, a similar concept to Sony's Playstation Network which entices users with free regular games.
But Microsoft executives still failed to detail Xbox One's hardware and its perceived failings, leaving gamers largely in the dark about what to expect from a hardware persepctive when their new console hits Christmas stockings later this year.