Groan....

Still, it's a slow day
No. The DoF is set for a given print size and distance, not any print size and distance. As the print size/distance varies, so the perception of DoF will change
Apart from the "No" I agree and that's pretty much my point. Thanks
I don't agree with the "No" because I didn't say or mean that the DoF is set for "any" print size and viewing distance in isolation. What I said was "Once you've chosen your camera and lens and set the aperture and positioned yourself at a certain distance from your subject the DoF you will see at any print size and viewing distance is set." That's perfectly true. But read on...
The DoF will look different to you at different print sizes and viewing distances but how it will look to you at all of these sizes and distances is set when you pick up the camera and press the shutter.
You absolutely cannot predict the depth of field at capture time UNLESS you know the print size and viewing distance. DoF calculators make assumptions about the viewing distance and print size in their equations. Alter those assumptions and DoF will change.
Thanks. That's my point
What I actually said was "That's why it's important to choose your equipment and settings and shooting circumstance with the final output and viewing in mind." So obviously I meant that you need to know your output size and viewing. And read on...
My point was and is that it's important to know the output size and viewing before you choose and set the hardware and setup and take the shot.
If you don't believe me, take a billboard photo and view it from up close and across the road. Close up and the image is just blobs and will be "out of focus" (i.e. it has almost 0 DoF). From across the road, it will be "sharp" across the subject and intelligible.
Thanks. That's my point.
What you appear to be saying is that if you know the final output size & viewing distance, then you can optimise the equipment choice to give a particular perceived DoF output to the viewer.
Yes. Absolutely you can. Read on...
If you know you are going to be printing at A3 and viewing from 5 ft away you can select your camera and lens and aperture setting to achieve the result you want. It all seems perfectly obvious to me
What Richard and I are saying is that if you don't have a fixed output/viewing distance, the perceived DoF is not known at image capture time. BOTH statements are correct. What is incorrect is the belief that some have that when you capture the image the DoF is fixed for all viewing sizes & distances.
That's not what I said and it's not what I meant. Read on dude.
If you don't have a fixed output size and viewing distance in mind you should still know that the DoF you will get at any future decided output size and viewing distance
is decided when you take the shot!

How can it be anything else unless you are using a light field camera?
Once you take the shot the DoF you will perceive at A3 from 5ft away is set just as is the DoF you will perceive at A3 and 20ft. In each case the DoF is perceived differently but what you perceive in each case is still decided by the gear and settings and the scene and your distance from it when you took the image.
Shoot with FF and an 85mm lens set to f1.4 at 2 ft from your subject and print to A3 and view from 1ft away... shallow DoF is obvious.
Print the same image the size of a postage stamp and view from 4ft away... the image may appeear to have deep DoF.
Shoot with MFT and a 6mm lens set to f22 and there's next to nothing you can do to perceive shallow DoF unless you print it the size of the moon and view it from 1 ft.
These things should be no surprise and what you perceive in each case, although different in each case as you change the camera, the settings and the print size and viewing distance, was set when you pressed the button.
The output size and the viewing distance alter your perception of the DoF you see but the hardware and distance to the subject and the spacial relationships of the things within the image are set and different perceptions at different output sizes and viewing distances can only make the inherent properties of the image either more or less visible to the viewer.
Oooh, there's nothing like DoF to lead to endless hair splitting.
Yes. I am indeed saying that you can optimise your kit and settings to achieve the output you want and that what you will see at any output size and viewing distance you choose is indeed set when you press the button.
This is why I take a lot of MFT at wide apertures. The reason is that with a smaller format system I'm more likely to be using shorter lenses and to perceive shallow DoF (which I sometimes like) in small prints and on screen at normal viewing distances I need to use a wide aperture. For example when shooting with MFT I often use a lens in the region of 20 to 50mm and rarely use apertures smaller than f8 and indeed very often shoot at f1.4 to f4.
However, with a full frame camera the chances are that I'll be using a longer lens and may be shooting with reduced camera to subject distances and as a result I will probably be using apertures in the f4-f11 range.
This will tie in nicely with the crop factor as MFT and 24mm at f2.8 = (more or less) FF at 50mm and f5.6 and both setting are within the ranges I previously mentioned for the two formats.
The reason I posted, and as always with you guys I end up regreting doing so

is to try and add some balance to the view that DoF is decided by output size and viewing distance. Full stop.
What I'm saying is that it's hardware and how the shot is set up that decide what you see at the various output sizes and viewing distances you choose.
My point is that you should think about these things before you take the shot and not believe that the DoF is decided later by the output size and viewing as that's not the whole story. It's the END of the story.
The DoF you perceive at differing output sizes and viewing distances changes with output size and viewing distance but overriding the whole experience is the kit and its settings and the spacial relationships when you took the shot.
And to get back to the OP and the example images I posted...
When I took the FF shot at 50mm and f5.6 I had a good idea what the image would look like and I knew that to make a very similar image with the Panasonic G1 I needed to use a wide lens and a wider aperture, hence 24mm f2.8 on MFT = 50mm f5.6 on FF.
These two images will look very similar no matter what the output size and / or viewing distance until you go beyond what the hardware can do and print them the size of a barn by which time the G1 image will probably fall apart first.
We do come at this from different angles and my point as usual is just to add a different view and balance and that is that YES output size and viewing distance are what decide how the viewer perceives DoF... but (Drum Roll)... what you perceive at any output size and viewing distance you decide on is set when you press the button.
Cup of tea time.