I appreciate the response - I really do, but I don't get the same outcome when I follow your steps.
Your method does eliminate the 0th step - unlocking the document. That gets me to:
1. Open the document you want to change. Nothing different here.
2. In the window just to the right of the file name is a hidden down arrow. Click on it and select duplicate. You do not have to unlock the file. Do not select file duplicate from the menu bar.
3. A duplicate document opens - sometimes stating that there were issues and asking if I want to review them, sometimes not. (I'm guessing this is because it's a Pages '08 document being opened with Pages '09).
4. Nine times out of ten, I'm still prompted at this point as if I've made changes to the document, so click through the dialog to specify whether I want to "Duplicate and Revert" or just "Duplicate." Maybe this is because I'm often opening older documents and Pages is making some kind of changes behind the scene when it opens. Regardless, because of the duplication process, I have to execute this step almost every time for pre '09 docs.
5. Make all the changes you like and close the document. A window will appear just like if you selected save as in SL. - Yes, this also saves a step, because you don't have to save and then close, thanks (but see note below.)
6. You can now rename the file and select where you want to save it to and the file type.
7. Close the original window - do this step whenever you want, but it's still an extra step.
Now many of these extra steps may be a function of my needing to work with Pages '08 docs, but the fact remains that the problems wouldn't exist if I could still just use "Save As..." It is a separate but equally disappointing issue that two versions of the same product can't play more nicely together, assuming that's why changes are detected before I've ever made a keystroke.
As for that saved step at close: While transparent backup of a version is something I like, transparent saving of a version at close is unintuitive (to me, personally, and aparently to a great number of us). If I don't want to save my changes for whatever reason, I now have to do a roll back, and if I do want to save my changes, I still find myself hitting Cmd-S before closing. Why? Because from an interface perspective, closing just doesn't feel like saving. I'll probably stop doing that over time, but closing to save reduces an action at the cost of introducing a layer of abstraction. I'm usually all about simplifying, but sometimes taking something out of a process does not equate with simplifying the process. The "Don't make me think." mantra may be bad in a societal or political context, but it's the right attitude when designing tools.
Things change and it's often a good thing, and whether or not this is good UI design is a matter of opinion. My personal point of view is that this was a step in the wrong direction if for no other reason than that it doesn't account for as many scenarios as Save As... I'm basing that statement on the fact that I get variable behavior across document versions and across apps. (TextEdit has different problems from Pages, for instance.)
Variable behaviors require me to disengage from production to focus on the tool. And I (and many others) simply do not like the distraction. Will we get over it? We may have to. I'm "over" the passing of my dog, but I still miss him. He was a good dog, and he fetched better than my cat - who really does fetch when she's in the mood. I think you can see the analogy.
These forums are great, though: you've given me a way to eliminate two steps, so thanks again.