I hope they add a run/walk speed modifier to the game. A lot of us like to look through all the nooks and crannies and it can take forever at the default walking speed. Personally, from the gameplay trailers, I feel like the game is looking beautiful and is definitely a step up from DOS2 so I'm cool with the default speed at first, but when I'm combing through everything to make sure I've gotten every piece of loot, and spoken to every NPC, I want to be zooming through the map because no matter how pretty the environment is, it loses its sheen when you're backtracking for the 10th time to make sure you didn't miss anything.
I know mods will come later to add this functionality but I definitely hope it's there from the beginning.