When they say "spin off", they mean just that. Spin it off to someone else and no longer own it. It would still operate as Delta Connection, no one would know a difference. Delta owned ASA and spun it off to SkyWest. Still part of the Delta network, just not owned. It would be like US Airways selling Piedmont and PSA (which they own)to another Express carrier. Comair (or any other regional jet provider) does not have its own routes, those are Deltas routes to put whoever they want on them.
Last thing US needs is more Express carriers and outsourced mainline jobs. They drag the product into the gutter and lose customers, particularly Mesa. Morale will never be good while Republic is on the property with thier direct replacement of mainline jobs. US should be flying all of the EJets and PDT/PSA should be flying the Q-props and CRJs.