Rhikter said:
The clone project was a failure from Palpatine's POV. He started to get paranoid about the clones betraying him, so he had the program discontinued and that's when the Empire started recruiting and training its personnel.

I read it on Wookiepedia once. Maybe I'll see if I can find and post the exact quote later. I won't right now though, because it's late where I am.

Be careful using Wiki for reference. Check the sources cited. I'll believe it, though. Just bear in mind that: 1) The current EU stance is that there are still clones making up the bulk of the Stormtrooper corps, and the 501st is entirely Jango clones; and 2) the Emperor evidently still liked cloning enough to clone himself and leave the Mount Tantiss facility on Wayland going.

--Jonah