Cult of Mac writer Mike Elgan recently detailed the years-long process that convinced him to switch to the Mac. His story is fairly typical of many switchers: Once a die-hard PC evangelist, his first Apple product was the iPod, which he appreciated for its ease of use. The iPhone eventually convinced him to ditch his BlackBerry, and the iPad was the be-all, end-all of tablet-based computing as far as he was concerned. Finally, using his son's iMac convinced Elgan to switch away from Windows completely.
As I said, it's a fairly typical switcher story... up until you learn that Elgan used to be the editor of Windows Magazine during most of the 1990s. It's hard to be a much more die-hard Windows enthusiast than that without having Microsoft's logo on your business cards and paychecks.
The things that kept Elgan away from the Mac platform are fairly standard: familiarity with Windows and reluctance to learn OS X, not wanting to be dependent on Apple for hardware repairs, and not wanting to self-identify with the "fringe" elements among Mac users. But eventually, actually using Apple's products on a regular basis convinced the former Windows enthusiast to switch. Outgoing PCMag editor Lance Ulanoff is on the mobile side of this roster, as he's switching from a Blackberry to the iPhone.
The "halo effect" of iPod users becoming enamored of Apple's smaller gadgets and switching to the Mac shortly after has been well-documented over the past seven years or so, and with the introduction of the iPhone and iPad this effect has intensified. Apple's efforts to bring some of iOS's functions to the Mac via OS X Lion can be viewed in this light as a shrewd move to amplify this halo effect even farther. People who are already familiar with the iPad's touchscreen interface may take one look at a MacBook Air running full-screen apps or launching applications via Launchpad and think to themselves, "Hmmm, maybe switching to a Mac won't be so hard after all."
Just don't spoil it for those potential switchers by telling them about the Finder.