Obviously, this isn't true. Their underlying architectures are quite a bit different, Gnome looks different than the 7 UI, etc., but to an average 17-year-old, there just wasn't any meaningful difference between the two operating systems.
The other day, I posted a blog titled "Windows 7: Good enough to pay for?" I described how I'd installed the Windows 7 Release Candidate on my son's computer for his take on the OS after living with Ubuntu 9.04 (and 8.10 before that) for a few months. It's summer break, so he basically spends every waking moment when he's not actually interacting face-to-face with friends on the computer. No better time to have a kid do some serious testing, right?
I asked him last night about his initial impressions of Windows 7 and, in typical teenage fashion, as he was bouncing between Meebo windows and browser tabs, he said it was "nice." I managed to extract from him that his favorite feature was that he was able to use his Zune with it, something that had never worked terribly well with Ubuntu. Otherwise, he said, "Windows 7 is the same as Ubuntu; there just really isn't anything different about them."
Of course there isn't. He lives in a web browser. The underlying OS is irrelevant. He has no need for Office 2007 and I expect his next portable music player will be platform independent.
For some, Windows 7 may, indeed, be good enough to pay for, especially if they are power-users of Windows-only software. For my oldest son, if he gravitates to any machine, it's to my Mac because it's so easy for him to create and share video content. For the average student, though, the old Windows vs. Mac vs. Linux debate may finally be dead. For someone who "hated Linux" a year ago to now happily switch between Windows 7 and Ubuntu in a completely transparent way certainly signals an end to that age-old flame war.