Hi Lasse,
You are correct -- layout information is not part of the XMI specification. However, what we normally do with our documents is (you're going to hate this) do the modeling in Rose or XDE and then copy the diagrams into Microsoft
Word documents... The diagrams are copied as Windows Metafile's (graphics files) and not XMI.
XMI is meant to help
exchange data between tools like Rational Rose and Together/J, or XDE and some custom code generator. It's a way of representing the "Design elements" like the classes, their connections and associations, etc. apart from the layout aspects. Thus, as Howard notes, we use XMI internally in WebSphere Studio because what we're conveying between the different Studio plugins is the relationship between classes (and even instances, which are also representable in XMI).
Hope this helps.
Kyle
[ December 13, 2003: Message edited by: Kyle Brown ]