I wonder why. If you are gonna be a military junta, and you want to keep your job, you don't do controversial things unless it benefits you. At least that's what the intelligent junta does.
So what is the benefit of letting Mubarak out? Does he still command a faction in Egypt, who will do something nice for the junta if the junta does something nice for them? Is there some personal connection between the junta and Mubarak? Like a blood relationship, a marriage between families, some mighty favor done by Mubarak back when he was running the place? The guy is 85 and in poor health, odds are he will be dead in a couple of years.
Or maybe this isn't so controversial in Egypt? After a year of the Muslim Brotherhood in charge perhaps old Mubarak is looking better to the average Egyptian in the street?
Who knows? Surely not the US media.