I'm sure at some point someone will think or ask here 'Just how many programs do you need for widgets?'
DesktopX, Rainmeter, Windows Widgets/Gadgets ( yeah I know), Google (didn't they used to be Yahoo) Widgets and there may even be more available. I think the answer is that we will use those programs that have or allow us to make the Widget/Gadget that meets our needs and as long as they can be skinned with the graphics of the desktop theme.
EDIT: I was a very bad boy, I left out Winstep Xtreme.