To give perspective on the cancellations for today:

By carrier:
Cancel #/% Delay #/%
616 16% 941 25% Delta
17 4% 41 11% Compass Airlines
16 0% 183 10% ExpressJet
4 0% 53 7% Endeavor Air

By hub:
198 13% 374 25% Hartsfield-Jackson Intl (KATL)
37 3% 101 9% Los Angeles Intl (KLAX)
25 3% 89 12% Minneapolis/St Paul Intl (KMSP)
24 5% 58 12% Salt Lake City Intl (KSLC)
17 2% 84 12% Detroit Metro Wayne Co (KDTW)
14 2% 59 8% Seattle-Tacoma Intl (KSEA)
13 2% 52 8% LaGuardia (KLGA)

ATL is taking the most of it in terms of cancellations and its primarily hitting MD88,MD90,717 operated flights the most. Many of them are the domestic short-haul mainline flights. The international flights are mostly operating, albet delays and out-of-position aircraft persist.

MSP & SLC are taking the brunt of domestic A319 & A320 cancellations, but they are much smaller in scale than ATL.

DCI carriers are are operating close to normal.

One can assume they are going to try to get the narrow body mainline airplanes and crews in position tonight as much as possible to reset and operate a more normal schedule tomorrow, however it sounds like lingering system issues are still creating throughput/capacity reduction system-wide.