This is awesome news! Untangling the Amtrak mess south of Union would be a dream come true. The talk has been going on forever. Hopefully the funds come through and shovels hit dirt on this finally.
Express trains to O'Hare are badly needed and would be a huge boost to the city as well. Attempting to do it on the Blue Line was never the right approach (thanks, Daley) since you would need to at the very least triple track the entire Blue Line, which would be either prohibitively expensive or downright impossible to do on the elevated structure and subway tunnels. Whereas using existing rail networks and having Metra operate it is much more feasible since the line and existing station (O'Hare Transfer) exist.
Much to MayorOfChicago's point, it is silly that you need to lug your suitcases across 1000 ft of parking lot to go from the O'Hare ATS to the Metra station. I wonder how much more it would cost to simply dig a tunnel and have a Metra stop directly underneath O'Hare, ala the Blue Line? It would be a huge timesaver and be much more convenient to ride only one train downtown, instead of having to transfer from the ATS. Alas, almost 100% unlikely to happen anytime in the near future. I will gladly settle for express runs to O'Hare Transfer from Union, if we are lucky enough to get that
