Hey, if you show me any piece of literature about the subject, I'll be convinced. I haven't seen any so far, but on the other hand, I haven't looked either. I'm not a Windows programmer.
However, common sense shows that the "current stable" is something like an alpha version, a lot of things can change until betas start coming out, and even then things can change until it goes "gold".
Also, that feature does not exist in current Windows and I haven't seen anyone make a plug-in (or application) for file transfers. I don't think there's any kind of API support, so... my guess is, someone would have to literally write a shitload of code to hook to the filesystem and monitor file copies or moves. In my book, that's an overkill. Too much trouble just for eye-candy.
Trying to write code for something in the early stages of development, on the other hand, is like planning a dinner menu without knowing what ingredients you have in the fridge. All in all, mate, I'd say "don't lose your cool". Windows 8 is a long way away. I suppose the Win8 first beta will be released around mid-January, and if all goes well, the RTM will be out around June. Again, from what I hear, the official launch will be in August. However, since you'd have to be insane to launch a product mid-summer, I think a delay of a month is more probable. So, we may still see the first beta in January, but I seriously doubt we'll see the RTM earlier than July. That's quite a long way, man. Besides, seeing Win8 I can't really see much point in going for an upgrade. The only thing I can see being worth it is the next-gen scheduler in the kernel. Everything else is just bling (and more of those fracking ribbons).
Live long and prosper...