I don't have a WP7 so maybe I'm missing something. I seem to recall that the mesh beta included a visual list of machines that were part of your...uh...mesh. I'd swear one of the options for a machine type was 'phone'.
That was the original Mesh. The current Mesh is a rebranded version of Live Sync (and before that, FolderShare) with only some of the functionality of the original Mesh added in.