Raincoaster would be referencing wordpress.org upgrading to WP 2.1.1, the newest version. WordPress.com is extremely secure and that is why all scripts that could be seen as a security risk are removed. The only risk you really run on wordpress.com is having someone figure out your password and that is why it is recommended to constantly change your password and use something that is not easily figured out.
As well, from experience, the most hacks on self-hosted versions of WP are really caused by user error and not WP itself. This includes wrong file permissions, running plugins that are not secure or just having other scripts running in the same place as wordpress. There is always a risk of it happening to you, but if you keep track of what you have and what you are doing, you should be OK!