Less hiring on the shuttle side than republic by far. For the past year, only a class of 6-8 a month at most. Most new hires have been going to EWR since it opened in June '14, but the last couple classes have seen a lot of IND. EWR or LGA, you might hold a line in a couple months if attrition keeps up.
Any base is attainable after a couple months of bidding, with the exception of ORD. Most junior there is 10/13 hire. If the new 175s go to Shuttle, the accepted theory right now is to replace the Q flying in EWR or DEN(or somewhere else "west"). PM if you have any questions and good luck