Copy text directly from text layer. Works above photoshop cs6. Copy following script file into /Applications/Adobe Photoshop CC 2014/Presets/Scripts (MAC) or C:\Program Files\Adobe\Adobe Photoshop CC 2014\Presets\Scripts (WIN). Assign shortcut for easy access (cmd+option+c / ctrl+alt+c)

Copy text directly from Photoshop text layer.

/*****************************************************************
 *
 * Copy Layer text 1.0 - by Praveen Vijayan! - http://www.decodize.com/
 *
 * Compatibility above Photoshop CS6
 *
 * Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
 * 
 *****************************************************************/
 
if(app.activeDocument.activeLayer.kind ==  LayerKind.TEXT){
    const keyTextData         = app.charIDToTypeID('TxtD');
    const ktextToClipboardStr = app.stringIDToTypeID( "textToClipboard" );
    var textStrDesc = new ActionDescriptor();
    textStrDesc.putString( keyTextData, app.activeDocument.activeLayer.textItem.contents );
    executeAction( ktextToClipboardStr, textStrDesc, DialogModes.NO );
 }

I confirm that it doesn't work with CS6, you get that:

Error 8800: General Photoshop error occurred. This functionality may not be available in this version of Photoshop.

• The command "" is not currently available.
  Line: 16
  -> executeAction( ktextToClipboardStr, textStrDesc, DialogModes.NO );

In that case, you will need that script: http://www.bram.us/2008/03/16/ps_bramustextexport-13-automatically-export-all-text-layers-from-photoshop-psd-to-a-text-file/ (works also with CS3 and CS6)