They use Intel motherboards. Or rather have intel make a "special" "dell atx" version of some intel motherboard etc...there were a couple discussions yesterday about dell "atx" motherboards not being standard atx.
I know that HP used to always use asus motherboards...like in celly pavillions they used the MEW-am
http://store.yahoo.com/justdeals/asmewmotsoci.html
"Dell" printers are made by Lexmark, lol.
I would imagine Dell is sort of like Nike....they dont actually MAKE anything.
JP