User blog comment:The Milkman/Extended Expectations, Part II/@comment-4939034-20120628162252/@comment-1221773-20120628211423

I don't think it's likely that any sequel games will rely on importing files from the original trilogy. Like other series such as Fallout, the Elder Scrolls, or Deus Ex which have games with multiple possible endings, BioWare will probably pick one ending (or even merge all three somehow) and use it as a launch pad for the sequel.