Some thoughts:
One thing that did surely confused me was that the version history does not provide you with stable versions, but was so far left untouched. This means that for example that although a version in the history is marked as sighted (http://wikixp.org/qa/index.php5?title=Berlin&action=history), clicking on such a version does not provide you with the stable version. Furthermore, when seeing such a version, the GUI is not shown. I think that showing the stable versions when possible would be much better. And more appropriate anyhow since currently, all templates are shown in their current versions instead of how they were when that version was created. Showing stable versions solves at least that problem.
The next question is, how much do we want to sacrifice for templates? I ask this because we are in the revert-thread here: automatic reverts are an essential tool for vandalism-fighting. However, as its automatic, people can't check the changes in templates. Thus, vandalism in templates can be transported in stable versions. So, what's worth more? Fast reverts or 100% accuracy in templates? Personally, I chose the first one.
All in all, I still think that the original idea is best:
i) Stable versions are defined as now (with templates and images as they were when created), but ii) If current is stable, show the stable text, but the last image and the last sighted template.
Chosing then the appropriate text for the box is IMHO a solvable problem, but all in all this is the most intriguing solution as is still allows templates to change in current versions, but blocks most of the vandalism in templates.
Bye,
Philipp