As far as I recall, all of my modules will work going back to 5.8 and previous, but I'm looking for opinions for cutoff lines... ie. what is it that makes you determine when not to support older versions?

I recently came into an issue that will force me to write three extra lines to be v5.8 compatible vs v5.10, which got me wondering how much work others will do before bumping the minimum version of perl (I'm sure requiring a module that you didn't write that uses newer features is likely a big one. Any others?).