The iPod didn't support Windows when it was released. Maybe Apple are doing the same thing here; I'm sure by not supporting Windows, they're able to get a better product out much quicker.
For Apple to commit to anything in advance, let alone Windows support for a brand-new peripheral, would be evidence of takeover by pod people, and thus not nice at all.
Windows support for the original iPod arrived two years later.
Again, they were testing the market with the true believers. The music industry viewed the 2-3 million mac users back then as a nice microcosm they could experiment on. If it failed, it wouldn't get much press because back then nobody used macs.
The iPod and the iPhone are only so popular because they embraced PC in all its ... glory. Hopefully they're already working on this.