As spoken on Facebook here Facebook Discussion
I cannot get some 3D formats files to be drag and dropped under VUO 1.1 - OSX 10.9, and blend meshes usually don't show up.
As far as I know:
BLEND and STL files cannot be drag and dropped to the editor.
However STL models will be loaded in the composition if the file URL is pasted in the node input.
BLEND is more curious. They usually don't show up. I got to load 1 or 2 of them (I will add them if I can find them back Steve)