The format of capabilities.xml has been changed. I have looked at the http://code.google.com/intl/da/apis/wave/extensions/robots/ and it is now possible to also specify the profile.
The new code looks like the following.
<w:profile name="Cartoony" imageurl="http://cartoonybot.appspot.com/public/avatar.png" profileurl="http://cartoonybot.appspot.com"/>
This is much nicer than using the profile servlet, which served the same informations. With the help of this new XML format you can delete your profile servlet. I cannot imagine a time, where the profile image needs to change dependant of which user is calling it. I don’t think you have the informaiton in the request sendt to get the profile informaiton. So thise values will always be hardcoded.
It does not provide much of a change in Python, since python already generates the document. Then we just need the Java API also to follow the python, so it also can create the cababilites based on configuration in a class file.