There are Jedi clones allready, but I don't no if they will be there in Ep3.
If you read Star Wars THE Heird of the Empire you see that there are Jedi clones.
Joruus is an exeple and Luke will be cloned to (Luuke is his name).
The problem is that when you you clone a Jedi there are mostly flaws. Thrawn will do something about this.
He finds out away to clone pueple in a shorter time.
And Jedi's in a "perfect" stage (luke is better than Luuke).
This sory is not written by George Lucas (but the book is made offical).
(It is a good book read it)