One important point:
FAQ: Who will have access to the information I provide?
Answer: If you decide, key information can be hidden until the time where the trial is completed. You can also upload confidential documents for record keeping, and those will never be shared unless you explicitly authorize it.
FAQ: How can I see whether a trial has been changed?
Answer: All edits are preserved and can be accessed on the "History" tab of any trial.
I have to admit, I am not completely convinced of the use of such a registry... I hope to blog more on that at some later point, but welcome comments and suggestions