There's a lot less information out there so far about Microsoft's other E3 2011 announcement, which is a new Halo trilogy of games featuring the Master Chief and Cortana.

The teaser trailer seems to pick up pretty much where the extra Legendary ending trailer in Halo 3 ends. Now, though, instead of just the ominous glowing metal sphere outside, the remains of the Dawn are on fire and the Chief has to bust out the cool new weapon and the built-in jetpack he apparently grew while in the cryotube in order to rescue Cortana from the wreckage.

The game is scheduled for a late 2012 release, and I'm sure there'll be more information available soon, as well as some time to dissect what this new CG trailer tells us.

Microsoft chose E3 this year for two Halo-related announcements. Both have been long anticipated and the subject of much speculation and controversy.

First, something old: The game that started it all is being "remastered" as Halo: Combat Evolved Anniversary. Still not sure how to punctuate that, maybe we'll get some guidance on it shortly. I'm still looking into the details, but it looks pretty much like what I've been expecting; a recreation of the original game's campaign using the capabilities of the Halo engine at least at the level of what was done with Reach. That should mean that all of the gameplay features possible in Reach should be supported in HCEA, even those not included in the original. We already know that this is true for at least one feature, which is XBL integration. Multiplayer and campaign coop will be supported over Live.

In a promotional video, 343i is talking about keeping the old gameplay, including the pistol; whether that just means keeping to the old game's balance, or also leaving out features that Halo 1 did not include, like boarding, remains to be seen. However, they are adding new things, like Halo 3-style hidden terminals that will tell a new story.

I think how 343 Industries achieves its goals with HCEA will give people a good idea of what they can expect from Halo 4.

HCEA is expected for release on November 15, 2011, exactly ten years after the release of the first title as a launch game for the original Xbox.

UPDATE: On the official site, Frankie gives a few more details about the gameplay, which will be untouched-- so it looks like aside from networking, no new features. The new graphics engine will run on top of the old one, and you can switch on the fly, sort of like what was done with the XBLA update of Monkey Island.

Here's what Frankie has to say:

So we did not DARE touch the gameplay in Halo. As a matter of fact, the gameplay engine, the physics, the controls (with some minor changes for the 360 controller and the aspect ratio) are identical. It is, in short, the Halo CE engine, but with a second graphics layer, a separate engine in fact, running on top. You can see this phenomenon yourself by pressing the back button at any time. The game will switch from old graphics to new, and back again, in real time. That in itself, is a bizarrely fun feature – one we constantly used to check to see if things truly were identical, or more frequently, simply to compare the two generations of hardware and see how far things had come. Although perversely, sometimes we switched back only to remember how good the original looked.

The lack of modern engine gameplay features I can understand, even if I might have wished for them-- but aspect ratio? Really? Why are all the screenshots widescreen, then, if this game is going to be 4:3? Now I'm confused.

UPDATE: Whoops, jumped the gun on the aspect ratio thing. That's one of the "minor changes" not one of the things that is "identical".