Not to throw a wrench in things, and you can take this for what it is worth, but I have hear from two separate UA GA's at two different airports that the plan is to be trained on SHARES and then SIX MONTHS LATER there will be training on a whole 'nother system that is a hybrid of the two.
Yes, basically the plan is to move twice by the end of calendar year 2012.
Again, could just be rumours that others have picked up on but I have heard it twice at different airports. Again, take it for what is worth.