Two finger scrolling is a pretty weak argument for "I need a Mac." PC laptops have their own touch scrolling mechanisms, and I wouldn't be surprised if some already had two-finger scrolling or some other type of multitouch-esque thing in it. The only reason Mac users won't like it is because it's meant to be an imitation of their beloved MacBook's feature.
As for viruses, as long as you use a router, or keep a firewall up, and don't visit illicit websites, you're pretty much fine. I run AVG on my desktop PC because it can handle it, but on my PC laptop I don't. I don't get any viruses.
Oh, and I used to own a MacBook. But I sold it and used the cash to get an Acer Aspire One. I got a notebook better suited to my needs and I had about $550 left over. So yeah, I think I made a good decision. With PC prices going down steadily, and Apple's prices only rising (except maybe on iPods), it's not surprising that anybody would choose a PC over a Mac. In fact, my MacBook is worth almost as much as my homebuilt PC and Aspire One combined, and my desktop is a decently powerful gaming machine.