From the devs: Decisions made in Awakening and all DLC (e.g. Witch Hunt, Golems etc.) will matter in DA2.3nimac said:What about Awakening? Also after ME2 im not sure this is such a big deal either.
DLC will matter [http://g4tv.com/thefeed/blog/post/706562/Hands-On-With-Dragon-Age-2.html]
Awakening will matter [http://social.bioware.com/forum/1/topic/141/index/3153797%26lf%3D8#3154321]
Also, Nathaniel Howe (the human rogue from Awakening) will most likely be in DA2, because he spent time in Kirkwall prior to Awakening.