I'm not fussed on playing a demo, i think i'll skip and miss this until the game actually arrives. Only played the Mass Effect 2 demo to get a feel for the game series in general.
Speaking of which, completed 2 earlier today. What a great game, and well worth the 40 hours i put into it. Already began a 2nd run-through, this time seeing if i can take it to 60 hours. Already have 1 noticable change, from something i did when i re-ran the 1st. Am planning a complete playthrough of both before the 3rd, if i feel like it.