I plan to support subdomains like "en.example.com" in the future major version (1.2). However, for what I have seen, it would be much more complex to support different domains, so it is currently not in my plans.
Although I have access to the last freely available version of WPML (2.0.4.1), I generally don't copy it as I find the code too complex. Moreover I did not succeed to make this part of WPML work (but I did not spend hours on it...).