I think that's unnecessary Dan. I believe Tony was just being a good citizen and cleaning up after himself. I suppose it's rather like 'using' which we all use frequently to clean up immediately.
I also tend to agree, this is just calling ::Release() on the RCW, which is a spun up, 'proxy' if you will, managed object, handling the COM goo plumbing for talking between the managed and unmanaged world.