In my case, first of all, my Mac mini that had been my desktop for 4 years had to be taken off line as my main desktop, because it runs Leopard which isn't good enough. I have a Windows Vista laptop that is actually OLDER than my Mini, and it had been sitting idle for a couple years. I had to do all the updates on it, and it's a little sluggish at times to come out of sleep or boot up, but it's better now that I updated it, and it's usable. I have wifi sync working on it with both my iPad 1 and iPhone 4S. I think part of it is where my laptop sits-wifi connection is about middle of the road, so sometimes it's fussy about starting the sync, but it does do it. I rebooted all devices to be sure. I have to laugh that a Windows computer older than my Apple one can accomodate the wifi sync, but my own Apple one won't. I'm not spending money on a new Mini at $699 when I have a laptop that works. And much as I prefer Mac OS, if my current Vista laptop gets too slow, I'd just as soon get an inexpensive Windows 7 laptop for $450 or so, because I don't have high power graphics and intense program needs, just basic home computing, occasional word documents, etc. And I'm not dropping a minimum of $699 to have a Mac OS desktop when there was no issue with my current one, and the absurdity that older Windows systems can do the wifi sync but Apple's own in my case won't. I think I should be okay for a while with this Vista laptop.
update: Xmas early at my house. My beloved saw me coveting the HP all in one touch screen, and bought me one. It's blazing fast, and very elegant. Yeah, I like Mac OS, but I'm having no qualms with Windows 7 on this very fast, smooth machine. Wifi signal is perfect, so must be a better receiver as it's in the same spot I had the Vista laptop. Wonder if Apple will ever have a touchscreen iMac, though it would cost a fortune for sure. And LOL, but this machine has more power than I've ever had, so who knows what I might do!