I believe this move is not thought out completely by the individuals in Atlanta.
Yeah, management wanted to duplicate the 3 Replacement Jets to every 1 Delta mainline, sort of like they have accomplished in CVG. But, CVG will still operate widebody jets in and out its station, DFW will have none.
DFW is unique hub for Delta, mainly a bridge connection hub, which now will have very few mainline jets to continue the movement from outline stations as well as the other hubs from both coast. One can only sell so many tickets from a small city operated by RJ's connecting to a smaller mainline jet.
This effect will cause "spillover" passengers who will then be picked up by the competition i.e American, Airtrans..ect... With one of Delta's highest yield markets DFW-ATL-DFW, it is confusing why they are cutting the number of seats in this market dramatically. And with the problems plaguing UA, now Delta is pulling all the mainline seats out of the DFW-DEN market and replacing the flights with the Replacement Jets. How many skis can one strap on the outside of an RJ?
Another great opportunity for Airtran or American to expand to Denver. Sounds like Airtran is already jumping into the ATL-DEN market.
Overall, I see Delta making a big mistake in DFW with these dramatic cuts in mainline service. Delta will be forced to reinstate the bigger a/c to accommodate all the RJ passengers that will soon come to DFW. Watch for major expansion and more new cities to be announced by DCI.