As for dumbing-down and consolization issues ... the next-gen consoles have seriously closed the gap to PCs in every way and this is becoming less and less of an issue as they mature...
This isn't new - almost every next-gen console has exceeded average PC specifications on release and then been outpaced as more powerful PC hardware arrives.
The real differentiator is the input device - mouse + keyboard for PCs compared to a console controller. Until a console ships with a mouse at least, there will always be a significant difference in the types of games suited for each platform.
In the case of D:OS (or the announced D:OS:EE), others here have highlighted the issue of inventory management. Doing stuff like crafting or modifying/enchanting items via controller isn't likely to be a quick or pleasant process. However the biggest difficulty I suspect will be interacting with gameworld objects. How exactly will D:OS:EE allow you to move a crate onto a vent, steal an item or combine items using a controller? Even
selecting an item is going to be hard with the lack of precision inherent with console controllers (having a popup menu listing nearby objects would seem the best course).
Of course, the way most developers handle such situations is by avoiding them in the first place, at the cost of simplified gameplay. That's why there's never been a successful, complex RPG for a console (in the same way that there's never been a successful, complex RTS) and presumably why dedicated console fans are asking for a D:OS port.
