Finally saw this last night, and I loved it.
Eitje, I thought one of the strongest points of the movie was how unlikeable Wikus was, at least at first. I felt sympathetic towards the aliens from the get-go, largely due to what a prick Wikus was. I also wasn't expecting him to remain as one of the central characters.
Also, this movie could easily have been called, "There Will Be a Sequel". There are way too many loose ends that need tying up for there not to be.