Defeating Diablo, Normal Mode (Wizard)

After playing around with the Barbarian (to Nightmare Mode level 45) I decided to toy with some of the ranged classes.  Although Demon Hunter is very popular, I decided to pick the Wizard.  I'm not sure why -- maybe I just liked his looks.

The Wizard leveled a lot faster than I figured he would.  My basic tactics were "gear up Templar, let HIM run in, and blast things from a distance."  I picked gear for overall DPS, figuring that the Wizard's job is to stay out of the way of things while someone else dies.  It worked quite well and he actually made it all the way up to Diablo (last boss) without dying -- even the icy battlefield didn't give him any trouble.  By the time he was level 30, I figured it was time to move onto the "let's get into Heaven and smush up the forces of evil."  The Barbarian (my first character) had trouble with the icy battlefields and I didn't get to heaven until she was level 34.

So what could go wrong with a Wizard character -- right?