F2N
they will keep them in 'active' duty as operational reserves. This means that they don't have crews or mechanics planned for them, but keep them and use them whenever need arises. I guess they will cover some check times with them and not wet-lease equipment as they did in the past.
If I had to chose between an MD11 and a 747 to fly a typical route, i'd go for the MD11 any time, as it costs around 35% less than the 74 to transport 10% less (in real life!). Only in the most volumetric environment you take the 747.