The latest news on the mesh front…
The Linden’s are telling us the mesh data format is going to change. This means the meshes uploaded to this point will no longer work. Mesh objects will have to be uploaded again. While this is a pain for many the change is made to get more stable mesh objects.

The changes have to do with renaming fields in the mesh data and removing some fields that are not going to be used. Additionally some meta-data is being added to allow mesh to rez faster. The document outlining Linden Lab’s mesh data format is started, per Runitai Linden.
These changes will roll out this week in ADITI. The changes will also necessitate a viewer change. So, you will need to get a new Mesh Project Viewer.