Closing 128 new Preview documents without saving I opened 128 .png files in Preview, hoping to use it to create a PDF out of them, as I believe was possible in earlier versions using the New from clipboard trick, but apparently, on Yosemite, not any more. 

Now I want to close the newly created documents, but it'll require me to click Don't Save 128 times. 

Is there any way around this?
As of Yosemite, at least, there's a much easier way. Just choose Quit from the File menu.

Preview will ask you if you want to review changes. If you say no, you're done!