Have you used Sage effectively in a certain type of course for a while? Do you want to share your voluminous resources and ideas with others? Why not propose a mini course using Sage at MathFest or the Joint Meetings? Especially if you have a few others who've used your materials too!
See
http://www.maa.org/meetings/miniguide.html for details. MathFest is due in early October, the JMM by late December. Collaboration is fun, too. I think there was already a probability-based one at the 2011 MathFest, so this is not an unfamiliar thing to them.
- kcrisman