Update comment for future removal of code

IPython/html/static/notebook/js/cell.js

@@ -566,10 +566,12 @@ define([
             var regs = modes[mode].reg;
             // only one key every time but regexp can't be keys...
             for(var i=0; i<regs.length; i++) {
-                // here we handle non magic_modes
-                // on 3.0 and below, things were regex.
-                // but shodl be string for config. 
-                // get rid of direct re handeling later. 
+                // here we handle non magic_modes.
+                // TODO :
+                // On 3.0 and below, these things were regex.
+                // But now should be string for json-able config. 
+                // We should get rid of assuming they might be already 
+                // in a later version of IPython. 
                 var re = regs[i];
                 if(typeof(re) === 'string'){
                     re = new RegExp(re)