You will always need a map of parameters if you have multiple parameters you want to pass. This however doesn't mean you need to present this complexity to the end users. I could see how you could extend the current editor for the human task node to not simply show one text box for the content parameter but show an additional option where the user could specify he has multiple ones and allows the user to specify each of them. This will then be translated back to an on-entry action creating the map underneath.
I'll see if I can slip this extension in the next few days.
Kris