There's a nifty nod to Dark Souls in the new Overwatch map Eichenwalde. Venture into the castle and into a room opposite the entrance, just off to the right, and you'll find a sword stabbed into a flaming mound. It is undoubtedly a reference to the Dark Souls series' iconic checkpoints.
The Eichenwalde Overwatch map, unveiled at Gamescom, is now available on the Public Test Realm for everyone to try. You access the PTR by selecting "PTR: Overwatch" from the "Region / Account" drop-down box above the big "Play" button on the Battle.net launcher. You have to download the PTR, and it's several gigabytes big.
I suggest you access the PTR to nose around Eichenwalde if you can, because it's not only a gorgeous environment - all crumbly castle and old German town - but also a complex one, with myriad routes and vantage points to know about.
There are choke points - one in particular outside the castle gates, which the payload batters down - worth familiarising yourself with too.
Eichenwalde goes live in Overwatch some time in September - maybe as part of the same patch in testing on PTR now, the one with Competitive Season 2, which has a pencilled-in start date of 6th September.