Hi there!
Today I created an online repository for Toki Tori 2 user created levels:
2trib.es/tokitori2_userlevels
Until we have full Steam Workshop integration, you can use this repository to download levels that were created by others, or to submit your own creations!
Loading a user level into the current build is a bit cumbersome at the moment, but we're working on a nice GUI which enables you to select a user level from within the game. Expect that functionality to appear in an update soon.
Feel free to mail me if you have bugs or some suggestions for improvements.
Cheers,
Martijn