I agree with everything Adam has said. The 1500 hr rule's major effect will be to get rid of most of the posers who want instant gratification and are only in it for ego boost of saying they are "jet pilots".
These 250 hr wonders who are so caught up in the "Shiny Jet Syndrome" that they are willing to take a Part 121 FO job on a transport category aircraft for $18,000 a year have destroyed the US regional airline as a place where somebody could aspire to a decent career.
Forcing everybody to apprentice in GA will not only give them a bit of real world experience but also weed out those who don't have a real commitment to flying.
It will also force the airlines to treat their pilots better as the inexhaustible supply of starry eyed wannabes won't be there anymore.