I know that Holliday is a free agent and can't be traded, this could happen in theory.
Assume that it will take a 5 year 100M contract to get Holliday to sign with the Reds. Maybe a little less, maybe a little more, but that's about what I am guessing it would take with Boras as his agent.
If the Reds trade Harang and Cordero, they will save $39.5M over the next two years. That almost covers Holliday's salary over the next two years. This would give the Reds two years to build a roster that could afford Holliday for the next three years, or possibly trade him after two years.
I think both Cordero and Harang can be traded without the Reds adding any cash, if no significant talent comes over to the Reds in the deals. They should be able to get a decent #5 starter and middle reliever, for them, which would fill the holes created by their trade. (Middle reliever replaces Massett or Burton, or Rhodes, or Fisher, or whoever becomes their closer)
But the key is that they then have the money to sign Holliday.
So the team would look something like this next year:
5th starter via trade or FA
They would be a little light in the starting pitching department, but Volquez comes back for 2011, and Leake and Wood should be ready by then if not sooner. And they would have a very solid offense and defense.
Anyway, just a thought.