Yes Linux does indeed just work on new Dell laptops now. I can personally testify that wasn't always the case. In years gone by it was a world of pain for the 1st 6 months while open source developed drivers for hardware they hadn't seen until the laptop was released.
That all changed when Dell started selling versions of their laptops with Linux pre-installed. And it didn't change a little bit either, in many cases it was a complete reversal. Drivers got released on Linux _before_ Windows - in particular Intel video drivers were repeatedly released on Linux before Windows in my case.
I presume that's developers are moving to Linux now. That was driven home to me just now when reading the Bling Fire post here, learning Bling Fire is an internal library used by MS's Bing search engine - then noticing all the instructions had a very nix'y feel, and the benchmark environment was Ubuntu.