It is not yet ultimate, but I have chosen to write my bachelor thesis about using COLLADA in XNA to display animated models. The topic has not yet been approved, though. I’m left to wait for my professor to decide.
Under the assumption that I actually will be able to write about this topic, I started playing around a bit. After at least two days of work I got my first custom model class running. I wrote a ContentPipelineExtension for loading COLLADA models. Right now only meshes and mesh parts with position, texture coordinate, normal and tangent information are imported and displayed. Material and effect definitions are also not yet imported.
Tonight I reached the first milestone: Loading the geometrie with above mentioned properties. For testing I assigned the correct material manually in the render code. In future, of course, the materials shall be imported and loaded automatically.
Simple COLLADA model with 3 meshes and one material
Support for skinned mesh animation is planned. But right now I got to improve the current version.
Bunkernetz 
Hi Mathias,
I’m also working on a project in which I need to upload a .DAE/Collada file into an XNA api,
We need a 3D interactive api.
Yet I don’t know if we are going to use XNA to do this or we move into the Java J3D environment.
Anyway let my know how is that XNA goes 😉
Hello Mauricio!
Well my C# and XNA 3.1 based implementation is essentially working. Right now I’m writing my paper, which will take approx. two or three more weeks to finish.
Afterwards I’m planning on creating an open-source project from it. But you need to asses what your needs are. For Java there already exists an open-source implementation of COLLADA 1.4.1.:
http://sourceforge.net/projects/whoola/
The decision can be made quite easily, imho:
If you want to create an application / tool, use Java which runs on much more systems.
If you want to create a game for PC and Xbox 360, use XNA. 🙂