User blog comment:ADour/AVENGERS: AGE OF ULTRON trailer is here!/@comment-4919678-20141024152611/@comment-4651179-20141025180758

I'm on the fence on thinking whether humanoid-eyes Ultron will be his final form or not.

In the trailer, we can see him using that form when he's recruiting Scarlet Witch and Quicksilver. Considering they will be with the good guys at the end of the film, that scene could happen in the first half.