The current feature that allows you to import an xmlns gives IntelliSense only when consuming XML via XElement or XDocument objects. You can type .< or .@ or ...< after an objcect of type XElement or XDocument and get IntelliSense for the available element and attribute names based on the XML Namespace.

I've spoken at several user groups and code camps on this subject and the next thing that everyone wants to do is to get IntelliSense when composing XML Literals, but that's not currently available.

Even if you have an xmlns imported and type something like the following, you will not get IntelliSense:

Dim myXml = <

Having the IntelliSense there would be extremely helpful.