Well done Bioware!
Let's talk about Dragon Age Origins first so I can explain what I feel they have improved.
The fighting style of Dragon Age Origins is something I would call "passive" combat. You'd have to stand in close proximity to the enemy and then your character would start swing it's sword. Kind of a pain. Dragon Age 2 fixed this. You can now mash your fight button to control your weapon. Then you have your talents that you can draw on when you want. Much better and less fiddly. The AI actually fights better but I haven't seen them drink potions when they need to. I hope they do because that was always a pain.
The graphics are stunning and amazing. There are voices! No more endless reading. Now I have just started this so I am not too deep into the story. You can import your Dragon Age Origins game save and have it be your backstory just like Mass Effect. Apparently, it changes the storyline a little too.
You can register at the Bioware site for some small free downloadable things for your game too. If you aren't already registered of course. I wish I had picked up the Signature Edition when it was available. Now I have to pay for the Exiled Prince DLC and am missing some items. Oh well.