SpaceClaim today announced its entry into the cloud-based collaboration space with a live 3D-collaboration product codenamed "Connect" which is till in beta. Here is a video explaining Connect.
The way it works, the host runs SpaceClaim on his desktop and invites other participants to a modeling session. The host holds the sole instance of the model and the participants can connect from any location using any device without need to download or save anything. The modeling is interactive so that if a client selects a bunch of faces on the model those faces are selected on the hosts desktop. This way CAD files are not sent across to each other and it ends up being collaboration through real-time 3D interactive modeling.
You can register for the beta here. The final product is due to be released in early 2014.