You forgot iLife, you forgot Express slot, you forgot the iSight, you forgot the weight, you forgot Magsafe, you forgot no pre-installed adware and crap, you forgot backlight keyboard, you forgot the sensor that turns off the MBP's hard drive if you drop it, you forgot dual-link DVI, you forgot IR remote (not just for Front Row, mind you, it works in almost any iLife app), you forgot everything that makes Apple nice and Dell just another PC company.
And aren't Lithium-polymer batteries better than the Lithium Ion that the Dell has? Oh, yeah it is!
Not to mention the confusing interface, and I'm not talking about the OS. The actual laptop has an interface. Power buttons, volume buttons, brightness etc. They look nice and integrated on a MBP, but unorganized and confusing on the Dell. Same goes for the interface ports.
Of course comparing features like bigger screen, better GPU to ease of use and industrial design might seem dumb to you, but for most people, they don't care about features alone. Users these days are looking for a good expirience with computers, which OS X can give and XP cannot.
The PC mantra that feature are the only thing that matters is dying. Look at iPod sales. iPods play music. No FM radio, no voice record, no complicated features. It does what it's supposed to do: plays music and automatically sync with your computer's music, and they sell like hotcakes. It's because people are tired of tech being complicated and confusing. The iPod is simple and just works.
Anyways, to summerize: the feaures don't tell you everything. The Mac will give you a better expirience.