searchSMB has an interesting article on using Wiki's for tasks that used to be done using basic workflow.
Wiki's are becoming far more common place and organisations are starting to accept them for corporate applications. An example given is the instance of a group meeting where notes are taken which are then sent around everyone in the meeting for approval/correction. With 4-5 people this might take a few days with normal sequential workflow. Put it in a wiki and everyone can update it when they want with an automatic history of what has changed.
Off course this could be done using a smarter workflow process in Lotus Notes. Using our workflow engine you would just set this up as parallel workflow rather than sequential. Off course there are complications to deal with such as replication conflicts but there are ways to manage this (another topic). I guess the point is though that a Wiki can be used for this purpose without the complexity of extensive workflow.
The one thing that seems to worry a lot of our clients regarding Wiki's is that anyone can modify anything. The point here of course is that there is a detailed history of changes automatically generated. Hence there is full visibility of what has been done by whom.