Here is another example of a real world use of SAVE AS that is defeated by the new Versions/Auto Save in Lion.
I've got a document I wrote in Pages, let's say a month ago. Today, I am making a new document and I want to pick up an object, let's say a photo, that was inserted in the old Pages document and use it in the new one. Sure, I could use Choose ... to re-insert the same photo, but maybe I don't know where it is, or maybe it's a time saved to copy the one from the other Pages document which already has some other attributes like a frame, a mask, a shadow, a text wrap and it's faster to retain those from a previous document than re-create them anew.
Now, here's the reason why I prefer using Cut instead of Copy when I have the older document open. When you use Copy, there is no immediate certainty that you have put on your clipboard what you intend to copy. Yes, of course you could open the Show Clipboard window, but notice that I used the word "immediate". When you cut the object, you can see what you've removed and the point here is that, for the last 28 years, I have known that all I have to do when I close the original document is decline the SAVE option and it will be untouched by the CUT command I just used. I do this with Illustrator files all the time, probably 50 times a day.
So the problem with Lion's new auto-saving is that my old document is now "updated" in a way I did not want. I did not want a new version of it, and I don't need a new version of it. I only wanted the old document open momentarily so that I could CUT something from it and close it without saving it.
Now, before the Lion defenders attack me for using CUT instead of COPY, I just want to repeat once more that I used the word "immediate". If you copy the object instead of cutting it, you have to wait until after the succesive PASTE command to know if you've grabbed everything you intended - not too much and not too little. If your windows are too large to fit side by side, you have to toggle back and forth to verify this.
The cut command, followed by a Close Without Saving is ideal in such a situation. In Lion, however, you end up with an unwanted new version of your old document with the object removed ... unless of course you execute another now-necessary command to Revert it.