I guess October 4th will be Mortal Monday.

Yeah. Also MK3 is going to be in MAT2. I don't think there is a offical version of MK3. MK3 is a saga that has 3 parts.

MK3 was the official version of MK3, UMK3 was the official version of UMK3, and MKT was the official version of MKT. All different games, and all as official as each other.

In terms of what was canon storyline wise, i'd go with UMK3. MKT had a horrible storyline which was butchered to allow a lot of characters to return regardless of their background.
(this question could have been posted in the classics section)

I don't think Midway would delay the release date for MK:D just because it doesn't sound cool, so i'm pretty sure the date we've been given is correct.

You seem pretty new to the site as well, so welcome.

Yeah, MK3 had 3 parts to it, think of it as a continuation, like a show or something, or (I cant believe Im using this) DBZ and there never ending crap.

Well, as sad as it may seem, MKT WAS cannon... Except the characters with no storyline A.K.A. Goro and Kintaro, those were there for Kompetition. As well as Chameleon.