I was part of a screening for it in Los Angeles a few months back (Feb I think). So I guess they were still working on it for final adjustments because they seemed to care a fair bit about our impressions. It looked good. I'll go see it again when it comes out to see if they actually changed much on it since that screening.
There were huge delays during the animation process. A few people actually got fired and replaced to help streamline the incredibly complex task of animating the film. Anyone who saw Waking Life will remember the sloppy (yet appropriate) style of animation. Linklater wanted Scanner to be way tighter in terms of consistency and 'realism'... I think the animators were put into groups to work on specific characters so there look was cohesive throughout the film.
Basically the animation took way longer than expected, and I think it's now due for release in July.