I was wondering how to admin several WordPress installs from the same interface and came out with this simple idea of having a tab container where each tab would give access to the WordPress admin panel.
This can be quite simple to develop by putting together a jQuery tab container and iframes.
This could be further extended in a way that one single login would authenticate across all the WordPress installations. In this way we can manage the several installs from one single interface with full flexibility, i.e. we have exactly the same options as if we open separate windows and log into the installations.