From wikipedia:
That also includes the ending, because Weitz still intends to add to his version when there are no sequels.To what was posted in the media, the film was cut by the studio quite a bit earlier than it may have seemed. This meant that visuals were not all completed to a sufficient and presentable standard. To finish the visual effects on Weitz version of the film may prove to be prohibitively expensive. He's going to be handing in a version of the film and a budget to the studio; but he would be surprised if they agree to fund it. And they still hold the rights to the film, so that would be the only way a version would be completed.