You do not think it is relevant to PowerPC users to have the knowledge that they can still continue to run their PowerPC apps if they ever upgrade to an Intel Mac running Lion or Mt. Lion?
I did...
The problem with that is 1) You actually have to have CS2 to begin with. Besides myself, a majority here don't own the CS2 suite legally, which is why most in this thread were excited when they were accidentally offering it for free. 2) Parallels is $80 (unless you get it cheap in a bundle), and 3) Snow Leopard is like $25 once you count the tax and shipping.
You also have to take into account that this would also force us to invest in a RAM upgrade to run it efficiently, so you would be tacking another $50-100 to the cost to max out a 2008-2011 machine.
At that rate, you are just better off buying the Creative Cloud subscription, or investing into alternatives like Pixelmator, Aperture, and others. If you really needed to run CS2, doing it under a Windows 7 Boot Camp partition would be the ideal solution. It would run much, much better.
I have Photoshop 7, the first CS, CS2, and CS3 that was loaded on all the Macs I was given from my old school however they are not suitable for college level classes anymore because they now go beyond the typical photo editing and drawing features in the way they teach it to you. I had a hard time getting CS3 to convert back and forth from it to CS5 the other year with just InDesign. They want you to learn to do the steps right too, so you can't just rasterize everything and get away with it. If you don't save copies, you can easily destroy your file setup if you aren't using basic tools. Same thing in 3D files, always have problems getting previous years Maya files to open in the 2013 version!
It's nice that we can still run our old apps on a newer OS, but there are reasons why we don't. I also get that there are plugins that don't worth on CS3 and above that people are attached to. I use rendering software that doesn't work on Lion or Mountain Lion myself.