When buying a Macbook, I know I'll be able to get parts and service for it - often from a local Apple store - for several years. If I buy a Dell N5040 today, and need service for it 2 years from now, will I be able to get it? Dell's got a reputation for good service for businesses, but that's because they're paying a lot extra for service contracts and such.
Looking at http://en.wikipedia.org/wiki/Dell_Inspiron then looking at http://www.dell.com/us/p/inspiron-laptops - I don't see some of the Dell models on the Wikipedia site (granted, they may not be 100% up to date all the time) but I also see a long litany of model variations, none of which inspire much confidence in me. With all the differing parts that change between models, will Dell even be able to get the same parts for my model in, say, 3 years?
Some of this is just trust in the brand - I know Apple's changed their macbook lineup several times, but rarely enough to warrant an entirely new name change - usually just spec upgrades. There's a certain amount of trust I and many other friends seem to have in Apple because of the simplicity of the product line. Yes, it's better for Apple as well, to streamline cost/operations, but from my standpoint simpler == less cognitive dissonance. I say this as someone who grew tired of building my own desktops years ago, speccing out parts (and trying to find linux drivers for them during my linux years), and have gone more mobile. There's usually far less "build it yourself" in the laptop world, so you go with what's available from manufacturers. Apple's models have a consistency between them and over time which builds confidence in the brand itself, not just any one particular model.
Trying to compete on specs with new models being introduced quarter to quarter will not work - Apple competitors need to rethink their long term strategy if they want to win back customers. I still run Windows sometimes, but I don't need a dedicated Windows machine from HP/Lenovo/Dell to do it on, and I'm not sure what would ever get me back to that camp.
Would I pay a 'premium' price for a Lenovo? Possibly, but there's gotta be a bigger faith in the brand, and I don't have that right now.