There are lots of great options for todo-list tracking these days. Unfortunately, most don’t make it easy to export or import your data. Here’s a list of scripts that I’ve found to perform conversions. Please comment if you know of more!
There isn’t currently any way to export repeating tasks automatically via AppleScript.
My Python script to convert from Things to The Hit List
https://github.com/thepoch/ExportThings
http://forums.omnigroup.com/archive/index.php/t-13565.html