Deleting a file from inside Lion’s Preview.app In Snow Leopard it was possible to delete (i.e. move to Trash) a file directly from inside Preview.app using the cmd + backspace combination. (The same combination which is used in Finder.)
This was especially useful for files which had been downloaded to ~/Downloads and were opened automatically. One could have a quick look and then immediately delete them afterwards.

The combination also worked for TextEdit as well as some other programs. Now with Lion this does not seem to work anymore. Is there a fix or a new combination for it?
At present there is not a solution for this. It seems that this feature was removed from Lion. The reason for this we will never be sure.

For now you will need to manually delete using the mouse and trash can.