Did anyone think that maybe the construction set is being delayed because there are some things in Skyrim the Dev's don't want people to cheat and find? Stuff like the insect jars or some of the stuff mentioned in books. Maybe there are well hidden quests or unmarked tasks that havent ben found yet. Releasing the CS would just spoil it as there would be countless people (I guess just modders) that would stumble upon these things and, dispite the forums best attempts, word will still get round...
that, or they want o release some DLC first...

The Lego Scrolls: Skyrim

It was delayed because they are using Steam workshop, which apparently will let us download and install mods with a click of a button.

And yet, I seriously doubt they'll allow advlt mods to be uploaded.

With all sorts of offending material that can get on there.

Maybe that's a blessing in disguise, it will ensure sites like nexus are still needed.

Excellent point

I thought the first comment would be: "It's called the Creation Kit!"