I liked your division figure. There is just one little thing. Intuitively I assume that technologies near the divisor are more commonly used in all clusters: Sun, IBM and Oracle. Judging from the position of XML, I suppose you think otherwise? Or do you have a different view on XML?(roughly translated from Dutch)
That is an interesting point. I think you're right that XML is commonly used in Sun and Oracle technologies as well. The picture says more about preference than actual usage though. I think the Sun and Oracle developers only use XML as a necessary evil in order to be able to communicate with "exotic" platforms like dotNet. But if they would have the chance, they'd use RMI over IIOP any chance they get.
The Oracle guys are a whole separate chapter. I think they have a very thorough grasp on relational modeling. I usually question their object oriented modeling skills though. And I think they are not keen on semi structured documents (XML) because they're hard to store in an RDBMS.
Your last question hits the key point: most likely I have a different view on XML. Using a little bit of XML for configuration, WSDL, SOAP or BPEL is not really intriguing. Especially not if the platform puts a lot of effort in abstracting away from underlying XML technology. What you'll see on this blog over the next few weeks is the exact opposite: I'll be abstracting away from the underlying platform and focus on the XML itself!