Let's fill in the blanks. It's funner that way.
In terms of scope, Dragon Age: Origins and Dragon Age II don't even compare to the upcoming sequel Dragon Age III. Not only does it take place in the entire world of Dragon Age, with Fereldan and Kirkwall being mere specks in the distance, but it will apparently encompass both Dragon Age titles by having both Hawke and The Warden Commander meet as well as resolve the "templars vs. apostates" issue brewing beneath the surface.
Players will journey through exotic locations noted in the past, particularly Orlais and Tevinter, and may encounter Morrigan, who appears in a piece of concept art in front of a burning barn. (I guess she disapproves?) Where the Hero of Ferelden will likely not be a playable character, Hawke's story isn't over (it's uncertain whether that means Hawke is playable or not), though the Hero of Ferelden is still a major figure in the world in some capacity.
The protagonist for Dragon Age III will likely be an new hero who must cope with "saving the world from… itself", which will likely mean finding a permanent solution to mages potentially becoming abominations and discovering just what Morrigan's and her mother
Fleming's Flemeth's roles truly are. They have a mother-daughter relationship that goes way over my head. Hopefully, that means an adventure with plenty of encounters against enemies who don't magically appear out of thin air (Dragon Age II, I'm looking at you).