We'll probably know more about this...
IGN has since amended the story to say the original report came from IGN Russia, and now writes "We're committed to getting the full story and will be updating this piece with more information as it develops."
I could probably get my fill with just the games scheduled to release on October 7th right now.
But offtopic aside: I remember the E3 2013 Forza 'gameplay'; so that's why I wrote CGI next to the possible halo 2014 footage: it will be completely beefed up, and has the possibility to have gaming blogs write for days about how great the graphics are. Halo 5 won't come out until Q3/4 2015 anyway, so it would only mean more XBox1 sales; an eventual backlash won't matter at the end of 2015 so they will go all out on Halo5, seeing as it is the most platform-defining game.
Also I expect Quantum Break to make a big splash; with graphics even exceeding the reveal footage, for example the environment in the trailer will look almost indistinguishable from the real-life footage with the real actors.
If Forza Horizon is playable for the press, then it will look different to the trailer.
That are my E3 predictions for the day
If there is a big Xbox 3rd party exclusive, it recently occurred to me a very likely candidate is Mass Effect 4.
A higher up in development of ME 4 already tweeted he'd be at the show.
Another name that's been thrown around is Fallout 4, but i feel like that one is too big to go exclusive. Plus ME has a history as a series with Xbox.
Probably would be a 6 month timed exclusive not a true exclusive.
Well, in case you haven't seen it EA did make all time, true exclusive deals regarding Titanfall. I think Titanfall could be a bigger title (more expensive) than ME4, so I think ME4 as an exclusive game is believable.
EA made that deal on the 'we're going to sell a billion units' optimism, I think that's long since disappeared.