Custom Graphs in Dashboards

I'd like to see the ability to have a dashboard widget that contains a script (powershell in my case, but whichever) which produces a JSON dataset so custom graphs can be produced.  My specific need is to pull historical data, perform some transforms, then create a graph, HTML, or table with the resulting dataset.

{
	"dataSet" = [
		{"time" = "09234920934", "value" = "3.4"},
		{"time" = "09234920935", "value" = "3.8"},
		{"time" = "09234920936", "value" = "3.2"},
		{"time" = "09234920937", "value" = "2.4"},
		{"time" = "09234920938", "value" = "2.7"}
	]
}