Because the Adventure is so wide, it'll have a very different feel than any other
DCL ship. If you look at the Royal Oasis/Icon ships or the MSC World ships which have similar GT size, there's enough room to fit two pools side by side.
And since this ship was adapted from the NCL Breakaway class, you can probably imagine that there'll be a very large Concierge area and interesting cabin configurations (NCL has lots of 2-bedroom suites in the Haven, for instance). Also NCL had so much space on the Breakaway/Breakaway+ ships (which are still considerably smaller than the Adventure, BTW) that they had room for laser tag and go karts. I don't think DCL will launch a ship with go karts, but I do think a very large waterpark that competes with Icon of the Seas is a strong possibility, and a much larger successor to the Aqua Mouse seem likely.
I also wouldn't be surprised if DCL announces a 2nd ship like the Adventure (or a ship modeled more closely after the Royal Icon- or MSC World-class ships). The recent earnings statement said something to the effect of the market being able to bear more ship expansion? And with everyone launching megaships, I wouldn't expect DCL to launch a 4th Triton-class ship. They'll either do Adventure 2.0 or go even bigger.