hmmmmm.... well, despite searching I have never managed to find an answer to my specific issue with the new Save feature, and although I prefer the "Save As", I found adjusting to the new Save feature not too bad for my personal work flow.
I do not really find the versioning of the new Save useful, can only think of a couple of times it's actually been of any use. Though in the Applications where it's use would be useful it doesn't exist, a save a version would be very useful in Logic Pro and in Adobe After Effects, but they still use the old Save As.
My issue which is related but not really mentioned is the fact that in Lion when you duplicate a document to make a copy of it (to achieve what you would with Save As), when you select to save the created duplicate you are presented with a Save window that takes you to the directory of the last opened document. Which is fine if you opened the document with the Open option from File Menu, but if like me you mostly open your documents from selecting them within Finder, the Save window presented is the previous document saved, which generally is somewhere completely unrelated and is incredibly annoying as often I am not certain of the location of the original file, which leads me to have to use Spotlight to find it…
Save As was also good for displaying the location of the currently open file if you wanted to find it in finder.
And no, the previous comment is not correct, Save As has not returned in Mountain Lion, though I thank the previous user for mentioning (checking what you said on my Laptop I have installed ML on made me realise my problem was fixed in ML) that as the issue I have just outlined has been fixed in Mountain Lion, it now functions as had done in previous versions of OS X, that clearly was a bug.
There's a few issue with ML at the moment so I will not upgrade my Mac Pro for awhile, though hoping ML will remove some of the instabilities that still exist with Logic Pro in Lion.
And as for KOENIG Yvan, he really needs to be ignored largely, yes! you do have to upgrade to Lion if you need certain new functions it includes and sooner or later you will have to upgrade as Apple will force you to due new hardware requirements. He seems stuck in some arrogant defence of Apple which is really not helpful to anyone, if these were not serious issues then so many discussions and complaints wouldn't exist, and why the **** should you have to go to the hassle of backtracking after installing anyway. Everybody has different needs and workflows. What works for one person doesn't necessarily work for another. Personally I don't have too much of a problem with the new Save function, but there is no reason as far as I can tell why it couldn't have been incorporated as an additional function as well still keeping the Save As function. Why replace a function when you could just have both options, it should be about making software as accessible and useful for as many people and situations as possible, not forcing people to work in a certain way to the dictates and perspective of the people who created it. A lot of the problems created seem to stem from the developers deciding how the software should be used and not taking into account and or allowing users to use software as they find is most useful to them… I am sure it's a complex process, but it's something that seems to have become more prevalent recently, the rigidness of certain apps, largely Apple apps I might add.