After having read through the last issue of the Objektspektrum magazine I was really amazed! Kanban seems to be what we've often (partly) done without having a name for it: pulling tasks, optimizing the flow and bringing the team together. Although Kanban still covers much more than that.
Even Scrum uses a few aspects of Kanban but it is different concerning important issues: Kanban doesn't require a homogenous team, fixed iterations and a completely new managerial culture as Scrum does. Therefore it could be used for a soft migration path to adapt some kind of lean or agile software development and is in my opinion highly recommended for managing maintenance teams.
I recommend everbody who is involved in managing software development to have a close look at Kanban.
For the one who is deeper interested in Kanban: Just on time the first Kanban training courses (adapted for software development) are available (the first one I found nearby googling).