This is *my* current temporary fix to get SugarJS's static method additions working in typescript.

tmpSugarFix.ts

/// <reference path="../path/to/sugar.d.ts" />

/**
 * Usage Examples:
 *   sgObject.isArray([1]); // -> true
 */
 
declare var sgObject:ObjectStatic;
declare var sgNumber:NumberStatic;
declare var sgDate:DateStatic;
declare var sgRegExp:RegExpStatic;

eval(
	"sgObject 	= Object;" +
	"sgNumber 	= Number;" +
	"sgDate 	= Date;" +
	"sgRegExp 	= RegExp;"
);

Just realized that regarding the second point, you could actually just copy the definitions over from Date to DateStatic (maybe that's what you did).