User blog comment:Abyssal Horror/Mind blowing theory/@comment-4964060-20130725182514

http://warhammer40k.wikia.com/wiki/Warhammer_Fantasy#The_Warhammer_World_and_the_Warhammer_40.2C000_Universe

Right, well in that article above it does state that in earlier editions of both Fantasy and 40k that they are connected. However in later additions they have tried to move away from and create separation between both universes. Mind you this article is quite old (as it hasn't been edited since 2010) so its info isn't up to date.

As for my own opinion, I say no. It doesn't fit well in my mind. I mean really,  have a whole bunch of guys fighting orks with swords and crossbows when the rest of the universe is fighting them with power weapons and warships? Yeah, no. I'll lock myself in a Blackstone Fortress before I believe that.