As a DM, sure, there was some good stuff there.
BUT, I:
Am also not seeing much
Do NOT like that fiction in there
Before this preview, I was pretty uninterested in Threats as well. I thought the fiction would fill space without adding a lot of value. But having seen it, I'm excited to get it. That tower is awesome, and the fiction does a great job of showing how you could use it in an adventure, without the boring "it could do this... it's been said that..." of previous books.
I think what we're seeing here is Wizards figuring out what to do with their physical books in the age of DDI. This looks like it's going to have real value even to someone with a DDI subscription.