Right now there's a "No Comment" radio button in the auto-comment dialog for deleting a question in Review-beta. However, it's possible to just vote to delete and not leave a comment by hitting the delete button. It seems like it would easier to use if there wasn't a "No Comment" choice, but rather a revised wording on the delete button (like "delete with no comment" if no radio button is selected).
Sorry for the messy mouse writing ;) I know this is a small change but I figured since this just showed up it smaller suggestions wouldn't be so bad.