First off, the statement regarding Delta as the "Axis of Evil" has caused me to lose a lot of my respect for David Siegal. In the United States' views (these may contradict with your country's view, I am just stating the United States'), Iran, Iraq, and North Korea are legitimate threats to attack/harbour an attack towards United States' interests. These countries have the potential to cause great harm to many of the world's people. On the other hand, Delta is trying to raise revenue in a time of financial non-prosperity. One way to do this is through code-shares, as now Delta will have much better access to several Southwestern and Midwestern communities through Continental and Northwest respectively. It's not like US Airways is innocent on this topic, they are doing the same thing with United; reaching more communities, and hence, raising additional revenue. What Siegal said was an absolute stupid remark in this environment.
He complains about overlapping of routes. Here are the new routes that would be overlapped:
Total: 19 Routes
That's not that bad. I even think what would happen is that DL and NW/CO would compete on all these routes, save for possibly EWR-BOS (where DL is flying 4 FRJs against 15 CO 737s, I think DL would dump EWR-BOS and reallocate the RJs and get away with it.)
And one more thing, Dave; if you think that you're going to get your alliance; DL will probably too. It'll be a take all or leave all scenario, I think.