I had not really noticed this or even recall it being mentioned.... it probably was somewhere in passing, but the gameboards being released in the Kill Team box set and Killzones all line up and connect up to make a larger gameboard.
The image above was put together by a reader and sent in for us. Huge thanks!!!!
via a Reader on Faeit 212
Haven't seen this mentioned anywhere yet that I've seen and thought it was pretty cool. The 22" x 30" gameboards in the kill team box and kill zone boxes are not only reversible but happen to sit together. If you place them next to each other they can make a bigger board for larger 40k games (without having to paint or buy realm of battle!!). The left two are either side of the main game box, the second from right is from sector mechanicus and the right hand one is sector munitorum. No doubt we'll see more that can make a bigger board. Just used the pictures from the gw website so they dont match perfectly but you can get the gist.