I don’t know if this helps, but many of us have our Scrivener projects saved on Dropbox. (When you create an account with Dropbox it puts a folder on your hard drive. Everything you put in that folder gets synchronised with a copy in the ‘cloud’.) If you did this, then when you get your Mac, you could install Dropbox, which will then place everything in your Dropbox account in a folder on your Mac.
Then, when you fall in love with Apple stuff, and you buy an iPad, you’ll be able to access all your Scrivener projects on the Scrivener iOS app via Dropbox
Alternatively, you could just copy your Scrivener file onto a USB stick, and transfer it to the machine thay way.
The number one thing to keep in mind is that your Scrivener project is the entire .scriv folder, including subfolders. It’s not just the .scrivx file that you click on to launch Windows Scrivener. So make sure you transfer the entire folder over – by any convenient method – and make sure the project works correctly before you dispose of the Windows system.
I guess what I was really wondering is, if I pull my old .scriv folder (created on Windows) up in a Mac version of scrivener, will it just come up with no problems? Does the Mac have a different .extension, or something?
The main desktop UI difference is the Mac treats it as a “package”, not as a folder, so you’ll see a Scrivener icon labelled “my-project” or “my-project.scriv”, depending on whether you’ve set the MacOS finder to show extensions or not—I always have them on—and you just click on that and the project should open. You don’t navigate down to find the “my-project.scrivx” file within the package.