Sorry, but no additional information regarding the position papers is available. Well, not much more is available.
Selecting a topic for the position paper is as important as the contents of the paper itself. Also, the lack of definitive guidelines (beyond those of length and format) is intentional; very senior system administrators – the people for whom the workshop is designed – should be able to write a suitable paper using just the information already provided.
The purpose of the paper is to demonstrate that you have good, solid knowledge and understanding of the field at both the nuts-and-bolts level as well as at the profession-as-a-whole level. During the workshop, participants are expected to quickly understand the issues presented by others and then offer meaningful and/or helpful comments about the issue; the position paper is a way of measuring your ability to do this (without the time pressure).
So just pick a topic, be it an issue or a problem, explain the topic, explain why it’s important, then take a stance on the topic and explain that.
Go back to the workshop overview.