I picked up this news earlier today via the Google Earth blog.
I've made good use of the 3D Warehouse and SketchUp for some years now... It's at least 6 years since I first started playing with SketchUp and this blog also features some awesome work by Noel Jenkins who has used it with his GCSE groups.
Here's the announcement:
Now it seems that there are changes to the way that 3D models created by people will be accessed.
It may be worth downloading some of the models that you think you will make use of now before they potentially disappear, or get harder to find and access.