Outside of launching a new console this is probably one of the most important E3s for Microsoft.  Even though they've managed to reverse mose of bad decisions they made at the start of the generation there's still the risk of the Xbox One becoming a distant second.  That's why I think they'll have a big exclusive announcement at E3 that will get a lot of people talking about the system.

With that in mind I'm going to predict that Mass Effect 4 will be Xbox One exclusive and here's why:

1.  The game is rumored to be releasing in holiday 2016

This is one of the biggest reasons I think it's going to happen.  Microsoft typically likes to have at least one big tentpole title for the holidays.  It's likely that Gears 4 won't be released until at least winter 2017.  There's a chance we could see Forza Horizon 3, Crackdown, Scalebound and Rare's new IP released at the end of 2016 but the lineup would be much stronger with an exclusive Mass Effect 4.  It would also be the perfect game to counter Guerilla Game's RPG that could be releasing at that time as well.

2.  The series has a lot of good history with the Xbox brand

Considering the PS4's lead it is likely pretty expensive to get AAA third party exclusives for the Xbox One at this point.  Mass Effect as a brand has always been pretty strong on the Xbox and Microsoft has published games in the series in the past.  Even if EA is unwilling to make the game completely exclusive they could well be open to having it a timed 2016 exclusive.  There could even be a deal to make it a true exclusive depending on how well it performed and how much money Microsoft is willing to give.

3.  Casey Hudson has joined Microsoft

He's now a creative director at Microsoft focusing on HoloLens but think about it, wouldn't it be cool to add HoloLens support to Mass Effect 4 to immerse people even more into the game?  Of course I'm not talking about HoloLens being required but that it would add to the experience and would help to promote the game even more.  Now who would be a better person to make this happen and also act as Microsoft's point man to the Mass Effect 4 development team than Casey Hudson?

4.  When asked about the rumor Mass Effect 4's Producer didn't outright deny it

There's been a rumor going around of the game being an Xbox One exclusive and someone asked Michael Gamble, Producer of Mass Effect 4, on Twitter if it was true or not.  People took his answer as a denial that it's happening but he could have easily have said "No, it's coming for PS4 and PC as well", instead he said "just a rumor" which could still be open to interpretation

Anyways that's my guess so what do you guys/girls think?

Timed exclusive could be possible.

"Exclusive exclusive"? Not gonna happen.

Shinobi a well known and reliable on Neogaf has repeatively stated that mass effect is not exclusive.

The whole Mass Effect franchise should have been exclusive to Xbox tbh.

But on topic, i'm 99% sure this won't happen. But then again, if it happened to Rise of the Tomb Raider, then why not Mass Effect 4?

Could be timed, which wouldn't bother me too much tbh.

Already confirmed multiplat.

What if they are timed though?, at this point timed deals are really both a waste of mone for MS and a waste for people like me who want a console with exclusives, if it's timed and I know it's coming to a platform I own then I see no reason to grab an XB1, it's got to be exclusive or no buy.

I'd rather they get or go for something big that has/makes an impact than small tiny games that hardly many are going to notice or play as much, games like that definitely exist on multiple platforms, sure that would be cheaper for MS but really that shouldn't be the point, they have the books, they just need to write the cheques.

Nah, any 3rd party game releasing during the holiday of 2016 will not be missing out on a userbase that could potentially be sitting at over 40 Million units and >50% marketshare. When you look at how EA titles have been selling on Gen 8 hardware, with Dragon Age Inquisition doing considerably better on PS4 as the perfect example, this would be an incredibly stupid business decision to make.

It will be PC, PS4 and Xbox One.

Highly unlikely given their last big game, Dragon Age Inquisition, did far better on PS4. They have no motive to make it exclusive, it would hurt them in the long run regardless of the money they got. So I say no, not even timed.

I doubt it. Mass effect trilogy was recently at $5 on psn. I assumed they want as many people as possible to try the franchise in preparation for mass effect 4.