If you haven't watched this video yet, you should really check it out.
This is just the beta, and I'm hoping that this is just an "Act 1 thing". But it appears that there's not as much randomization or larger maps like what I was expecting.
The beta is much like a game on rails (i.e. linear paths) where all outside environments are the exact same design, but with random placement of trees and mounds. Dungeons have more randomization, but they still use fixed points and identical passageways, so they're fairly easy to navigate no matter how many times they are generated (i.e. there are points of reference that help you select correctly when given multiple choices.)
Boss encounter areas are also static. Looking at all of this tells me that botting will be easier than I anticipated, and model editing more useful. With significantly larger maps and heavy randomization, exploits become more difficult, but I suppose they took this approach to take load off their servers (and increase game efficiency) during the randomization process.
VoidTester (see comments below) has updated me to a blue post about the randomization concern. Apparently, it is limited to Act 1 and it was meant to ease players into the game through a guided experience in the beginning. But, zones are much more randomized in the other Acts. Awesome news indeed.