I believe that Aikido should be done with your uke, not to your uke. So in agreement with Lynn, once you've connected, you move with them to disturb their balance and then let them fall whichever way they are going. If you work with the aim of trying to throw them, you will invariably jam yourself up as you try to make the throw work, trying to put uke in a place that his body doesn't want to or can't go.
I also believe that this is so for any technique, be it a throw, pin or lock. The more you try to do it, the less it will work.
I guess that means I'm in the "goal is not to throw" camp.