How do you "consolize" a hack and slash? I mean there's not that much to be dumbed down in the first place. DS2, while fun, was pretty much mindless.
When we talk about consolizing, I'd say the hugest issue is multi-directional inputs. A PC gamer has the ability to provide multiple directional inputs at the same time (WASD/mouse). How this applies to every genre is different:
FPS: In a consolized FPS game, aiming tends to be less critical (auto-aim) and movement is usually a before-and-after event. Such as running to cover, where you will then shoot from statically. In a PC FPS, players are often expected to be able to run and shoot at the same time while aiming much more accurately.
RTS: In a PC RTS, the gamer is expected to be able to pan the battlefield, while selecting units, issuing orders, controlling production and placing new structures. Honestly, I can't make any comparison to a console RTS because I've never played them. Anything on the console that I've ever played that could even be called remotely RTS was hugely dumbed down by comparison.
RPG: When we get into the RPG world, what we tend to see is that PC RPGs usually had a lot more inventory management. Control exactly what each character equips and change it on the fly. This is where you start to see the benefits of "click and drag". We also tend to see a lot more 'target-able' spell casting. This is to say, a spell you can cast and then dictate where it goes, as opposed to any sort of auto-lock on or completely automated spell. Perhaps I want to put 15 firewalls in a doorway, I can very easily with the mouse. Perhaps I want to teleport 1 inch and then after that, 5 feet - again very easy.
So because Dungeon Siege is an action RPG, it tends to follow the limitations of an RTS and an RPG. Often you will be able to manipulate the battlefield in an action RPG in some respect, zooming in and out, rotating, etc. Then you tend to be able to issue your orders to 1 or more units while also controlling where they move. You'll see a lot of target based spells and a lot of inventory management.
Now let's look at the gameplay video. First off, all we see is a warrior. You'll see the UI is very minimal since console players can't really click on much in a UI anyways. The inventory screen is very minimal since console players can't click and drag easily, replaced by a categorized list of items. Because the player is a warrior, we only see about 3 skills and nothing is target-able, just direction based (player is facing west, so swing west). We also note that the players movement is dictating all movement, meaning the person can't pan ahead or zoom out, the camera is locked behind the player much like an action game and likely the player can't move north and cast south or anything to that affect.
I don't know whether Dungeon Siege 3 will be good. I can say however that DS2, while a good single player game, was nowhere near as good as DS1. I can also say that it doesn't look like DS3 will play anything like DS1. And it seems fair to say that controls are consolized. Whether that is good or bad. Certainly, a gameplay video based on an archer or caster would be more telling.
I should state that, to me, DS1 will always be "the game with the wacky world". Where half the fun was trying to navigate the desert or survive the darkness maze. I always felt it was only partially a hack and slash, with the other half being sort of a mind fuck. The world was huge though and you could go anywhere, there weren't any limitations. That was what made it different from Diablo, that is how it stood out. DS2 lost these features wholesale.