As Engadget reported over the weekend, the iPhone is incompatible with the 64-bit flavors of Windows XP and Windows Vista.
Apple's iPhone specs page doesn't mention the incompatibility; it says that the iPhone will work with Windows Vista Home Premium, Business, Enterprise, or Ultimate Edition; or Windows XP Home or Professional with Service Pack 2 or later. Apple does acknowledge the iPhone's 64-bit Windows incompatibility on the iPhone support page in a foot note.
When will the iPhone be compatible with 64-bit flavors of Windows? I've asked Apple when and if it plans to offer a fix/update. So far, nothing back.
The comments over the weekend on Slashdot about the iPhone-64-bit-Windows incompatibility are worth a read. There's the "blame Microsoft" school. But there's also an equally, if not more, vocal "blame Apple" one.
A couple of posters note that Windows Vista was released to manufacturing in November 2006, so Apple's previous defense as to why iTunes initially wasn't Vista-compatible -- not enough time -- doesn't hold water. Some 64-bit Vista users claim iTunes now works just fine for them; others say it still isn't working right. Other posters say that Apple's hardly the only company not providing 64-bit Windows support and that there is still a dearth of software and drivers that support 64-bit Vista. (A quick check of the latest Vista compatibility list maintained by ieXbeta shows a lot fewer 64-bit incompatibilities than a few months ago.)
Anyone early iPhone adopters care about iPhone's lack of 64-bit Windows support?