Although I always thought Apple products were a bit overpriced, I realized that people were paying for quality. And I finally bit the bullet last week, just like you! It's definitely a great investment. Never going back to PC after what Dell computers have done to me.
I owned a Dell laptop for about 2 years (I think just over 2 years, nearing 2 and a half), and it broke down on me. It was a Dell XPS M1210 from late 2006. I used it constantly though for gaming and whatnot. It had an Intel T7200 processor (2.00GHz) and an NVidia GeForce 7400 graphics card (64MB dedicated graphics, and I think 256MB shared memory). It had an 80GB regular hard drive and 2GB of DDR2 667MHz RAM. The thing was awesome and relatively stylish... thick though. It worked well for me, but eventually it broke. I swore Dell off also after that. To Dell's credit, I did use the laptop nonstop for gaming and the like ALL the time; the computer was probably left on for 20 hours in a day, whether idle or being used. And all of our Dell desktops we've ever owned in the house have been excellent (one is still chugging along and it's over 10 years old! lol).
That said, I don't buy desktops. I don't think I'll ever buy an Apple desktop, unless if I swear off Windows and decide not to game in the future; then I may consider an iMac of all things. But currently I love having a very powerful computer, so I build my own custom desktops.
As far as laptops go... I'm an Apple guy now. The Air is my first (obviously). But that doesn't mean my next laptop might not be a regular PC laptop: if someone offers a laptop with features that rival an Air, I'll look at it for sure. But I doubt a competing product will exist for quite some time.
To say that I'm an Apple guy for laptops and a custom-built desktop kind of guy (Windows for that) is really just saying this:
I buy the best product for my dollar. I don't swear by any company. I will swear a company away if they prove to have poor business practices, and I may take certain things into consideration if a company has good business practices (ex. Apple's warranty service), but as far as products go... it's all about what is being offered. I don't like being biased about one thing or another. My little brother thought (and thinks) I was a fool for buying an Air. I, on the other hand, know that there is no other ultraportable which offers what the 11-inch Air has to offer.