Intel Centrino Atom becomes Atom, Atom still Atom, you're confused

Oh good, another marketing-speak change-up tossed our way from Intel. Apparently, the Centrino Atom naming convention is no more, leaving the in-house branded Menlow chipset used in MIDs and UMPCs essentially nameless. Atom, as you may recall, is the name of the Silverthorn and Diamondville-class CPUs. Got it? Of course you don't. No worries, that's why you've got us. You just focus on trying to understand the difference between MIDs and UMPCs and netbooks and ultra-portables and we'll take care of the rest.