[QUOTE=Jayjay] I think the touch object will soon support multi-touch, if it doesn't already.[/QUOTE]
It does already, and you can also enable mouse input as single-touch input for testing.
They're separate so if you want you can handle mouse input separately to touch input. Since they're very different forms of input I thought games might want to tweak their method of touch control and mouse control separately, which having separate object allows, or if not you can easily enable mouse input for the touch object and have both the same.