If I have html like this:
This is some text
First span text
This seems like a case of overusing jquery to me. The following will grab the text ignoring the other nodes:
document.getElementById("listItem").childNodes[0];
You'll need to trim that but it gets you what you want in one, easy line.
EDIT
The above will get the text node. To get the actual text, use this:
document.getElementById("listItem").childNodes[0].nodeValue;