Shouldn't handling of that (deleting/recycle bin) be in the platform specific versions of Java then? Or does Java have zero knowledge of specific OS capabilities?
I not a big fan of Java personally, but I have it installed because of two apps. The official F1 timing application on formula1.com and JWoWUpdater (two apps I can't live without).
Well to be honest, i dont think using a recyclebin as a backup solution is a good idea, ever.
So i might just make an option that zips your interface folder up as a backup.zip. Much like the WTF folder is now when you delete saved variables.
This would work on all platforms, and frankly its a better way of backing up stuff :)