Great idea. I just left a review. Was asked to register after reviewing. I registered and was brought back to the product page with no review on the page.
I expected the review to be posted. If it's in a moderation queue I'd expect to see a message indicating that's the case. And if the review didn't get saved I probably wouldn't leave another one.
Did you add a review or just a comment? Signup is indeed required for write-operations, but it should bring you back to the product page with the pre-filled comment. Will look into that later, thanks for reporting :)
I expected the review to be posted. If it's in a moderation queue I'd expect to see a message indicating that's the case. And if the review didn't get saved I probably wouldn't leave another one.