The last announcement of the conference was the most important, and the big reveal that had some members of the audience label the show "stunning".
The demonstration consisted of the 3D camera technology, Project Natal, which tracks body movements (including forwards and backwards) accurately, making a person's whole body the game 'controller'.
Several applications were demonstrated, including a sports-action mini-game concept in which the player kicks or punches back footballs flying at them, and a painting application which mapped actions such as throwing buckets of paint, finer brush strokes and the ability to make stencils using body shapes.
Finally, the "wow" moment came with Peter Molyneux introducing a video of a concept called Milo, a virtual boy who appeared to react to the gamer's questions and show emotional responses. The video also showed the gamer miming certain actions, which were then represented in the virtual space - putting on goggles, handing Milo paper, and swirling of water in a fish pond.
Molyneux himself - never one to shy away from ambitious projects - called Natal "true technology science fiction has not even written about," while Steven Spielberg also came on-stage to add his voice to the praise, noting that when he first saw the technology in action "gamer in me went out of my mind," adding that it was a "landmark" achievement.
The Games - Key Titles, Part One
The top of the show was dedicated to the platform's software slate, some of which was exclusive, some cross-platform.
First up was Rock Band: The Beatles, and the on-stage walkabout that the whole show was brought forward five minutes for - as well as a demo of the game, and reveals that Abbey Road would be the first album available, Yoko Ono Lennon and Olivia Harrison then appeared, followed (once they'd departed) by Sir Paul McCartney and Ringo Starr, neither of whom appeared to be particularly on message, saying a few words of thanks before departing again. A curious, if impressive, cameo.
Tony Hawk bounded on next, showing off the new skateboard controller for the Xbox 360, and talking a bit about his forthcoming title Ride, before the first real gaming highlight of the event - Modern Warfare 2.
The Activision shooter was demoed, running in full gameplay mode, in a snowy, mountain-top environment, with the player climbing up an ice wall before getting into the action, and then attempting to escape on a snowmobile. The game, as expected, looked very good indeed and on that evidence looks solid for a strong Christmas.
The next project from Bungie - Halo 3: ODST - was talked about some, before a totally new game called Halo Reach was teased. The latter title is being targeted for Autumn 2010, and people buying ODST will be eligible for the beta.
Games - Key Titles, Part Two
Final Fantasy XIII, first announced for the Xbox 360 last E3, was shown running on the Microsoft machine for the first time, with Square Enix going public on a Spring 2010 release date plan.
Shadow Complex, a side-scroller from Epic for XBLA followed, with an avatar racing game called Joy Ride for Xbox Live after that.
One of the most understated triple A games in the entire event was a brief video for Crackdown 2, which was confirmed as the first project for Ruffian, the company formed from ex-Realtime Worlds members.
Ubisoft then talked the audience through a video for Splinter Cell: Conviction, before another big reveal for the much-anticipated Forza 3, which will include the option to record and upload high-definition video, run at 60 frames per second, and feature 400 vehicles from 60 manufacturers.
Alan Wake rounded off that section of the event, with a video followed by a gameplay demonstration, and the firm date of "Spring 2010" given for release.
Games - The Metal Gear Reveal
In a move described by Don Mattrick with the phrase "We can finally say that our platform is complete," Hideo Kojima made a brief appearance to confirm to the audience that the next MGS title - Metal Gear Solid Rising - will definitely be coming to the Xbox 360.
It's the last of the big independent former PlayStation 3-exclusives that have now made the transition to multi-platform, and although there was no release date mentioned for the game, Kojima did reveal that Solid Snake had definitely retired, with Raiden featuring as the new game's protaginist.
For anybody that lives out their existence via Tweets and status updates, there was welcome news that the Xbox 360 would be integrating both Facebook and Twitter into the dashboard, allowing users to publish to the networks via their consoles - including shots from selected games (starting with Tiger Woods this year).
Additionally, a handful of service announcements were made in addition to the previously-announced Sky-360, including "instant on" viewing for Netflix users in the US, streaming free music via a partnership with Last.fm, and 1080p resolutions to be made available for all film and TV programmes in the renamed Zune Video service - all to go live "later this year".