The September 2007 issue MSDN Magazine contains an interesting article about changes to the System.Net namespace. Among the discussion about sockets and other low-level changes, the authors discuss support for International Resource Identifiers (IRIs) and their benefits over URIs.
I didn't realise it was possible to use non-ASCII characters in a domain name and while many DNS servers don't support non-ASCII domain names, Punicode provides a mechanism to work around this limitation.
So in essence, you can now take a domain name containing Unicode characters (like this: http://微軟香.com) and work with it directly using the URI class. This is certainly a great thing for international visitors to our web sites but as I only read English and French, I was really clinging to the English URLs as the last remaining way to identify our pages in SharePoint! Ah well, modern times, 'tis a global world...