I love Scrivener, but many times I read about some great stuff it can do, only to find that it only works in the Mac version.
I would like to have the same functionality – things like exporting to IndexCard, Dropbox, and things like that. Windows folks work cross-device too!
The Mac version has a five year head start, essentially. Synchronization features in particular only came to the Mac with the 2.0 release. Rest assured, our goal is to bring all of the Mac features to the Windows version as quickly as feasible.
Katherine
I just bought Scrivener on the basis of the Inspector Footnotes tutorial video (accessible from the Scrivener for Windows page) and was sorry to see that distracting inline footnotes still persist in the Windows version.
The option to hide them would be most appreciated as it’s getting hard to see my text through the fog of inline footnotes! I’m sure many non-fiction writers feel the same.
Other reasons too, surely? 
On the plus side, if you did buy WinScriv purely for the Inspector Footnotes, you just got a whole lot of other functionality for no extra cost! Awesome! 
Seriously, though: this is what the generous trial software period is for.
As for the “wish list” aspect, if it’s in the Mac version then Katherine’s answer remains valid…
One thing the Windows version does have which the Mac no longer does (due, sadly, to the way the OS X text system works) is a “Ghost Notes Mode” for inline notes. You can toggle this on to fade the notes when their text is not in focus, making them less distracting as you’re going through reading your main text. Format > Options > Ghost Notes Mode.
As others said above, the feature set of the Mac version will be coming to Windows, so inspector footnotes and comments are in the works. Most of the videos on the website at present are for the Mac version (though in some cases they apply to both), but we’re working on a series using the Windows version.