I'm not going to entertain the false choice between the through cars of the Pennsy to the CL or the daily Cardinal. The 2010 PIP show a $2M increase in subsidy in making the Cardinal daily, and less than $1M in the CL/Pennsy connection.
I assert that increased ridership since 2010 (which is well documented) mean that making the Cardinal daily would REDUCE subsidy, and that the CL/Pennsy connection would REDUCE subsidy. Therefore they should both be done ASAP -- they are both profitable moves!
Both of these are pretty small pieces of the pie, even for Amtrak. Amtrak can work on more than one thing at once. I'm guessing both are being worked on concurrently, and one happening before the other would simply be a matter of timing on which one can logistically happen first rather than preference for one over the other.
Quite likely both of them are waiting for single-level car availability. They both need additional coaches and cafes and sleepers. But the sleepers won't show up until 2016. Coaches won't be released by the West Coast bilevel order until 2016 or 2017. Cafes are available... except that they're going through installation of WiFi right now, which is also pulling sleepers and coaches out of service.
At this point, I'm kind of hoping for a big "Chicago East Coast Service Relaunch" in late 2017 or early 2018, featuring:
-- Through cars from the Pennsylvanian to the Capitol Limited (with associated improvements at Pittsburgh station)
-- Schedule "swap" of the Capitol Limited and Lake Shore Limited, both leaving earlier, as proposed in the PIPs
-- Faster schedule on the Lake Shore Limited (completion of Schenectady-Albany-Poughkeepsie track, signal, station, and platform improvements, and completion of MBTA upgrades Boston-Worcester)
-- Faster service on the Pennsylvanian due to high-platform upgrades of the Keystone line stations where it stops
-- Daily service on the Cardinal
-- Full dining car on the Cardinal
-- Slightly faster Cardinal schedule within the NEC (from removing Heritage cars)
-- Wifi on all Chicago-East Coast services
-- New Metropolitan Lounge in Chicago
and ideally
-- High level platform in Union Station Chicago (a proposed component of the Union Station Master Plan)
-- Twice-daily Pennsylvanian (under consideration by PennDOT)
....
There's a lot of stuff which is planned and in progress, much of which is converging towards similar completion dates. With some effort to try to expedite some of the components, Amtrak could throw a splashy "relaunch" of Chicago-East Coast service in 2017 or 2018 and get a boost in ridership.