What I used to do with BBEdit 8 and earlier versions was simply to  
have an AppleScript which opened a new file and saved it in a  
"temporary" folder named with date and time formatted like this: yyyy-
mm-dd-hh-mm-ss

This meant that I could always create a new "scratch pad" if you like  
which was saved in that temporary folder and could, if desired, be  
retrieved, however retrieval usually wasn't very necessary. I didn't  
want to do the "scratch pad" activities on an unsaved file because if  
the application crashed then I'd lose it.

It would be a great exercise for me to learn how to create this bundle  
myself in TextMate and so if it is not a good time for you to consider  
such a thing then it will be no problem at all.