They must be finding a lot of bugs. I think wrinkly has had 3 or 4 hopeful time tables for release.
In looking at the Wrye Bash forum on Beth, it looks like 1.5 has thrown them a curveball by changing the structure of update.esm. As I read it, they think it is the killcams.
What is with Bethesda? For the last 3 games (at least!) - Morrowind, Oblivion, Fallout 3 + New Vegas - the mod community has fixed bugs, improved looks, and increased the popularity, reputation and longevity of each one enormously. Yet it seems now that there is no communication from Beth to even give some consideration or a headsup on Update changes (other than a short beta phase) or provide some dialog to help the major mod teams prepare for changes. It's really starting to tick me off as I would never have played their games for half as long as I have without the modders out there!