I don't expect this to change under a new President; I expect this to be one of the ways of sustaining a Bush policy under the radar of US citizen awareness.
But if NATO countries object strongly enough, I think or hope that a Democratic President would be more open to flexibility.
One question is: what would a Democratic President's reaction be to a Europe-only military alliance? Almost certainly very negative, if only because the Republican party would use it against him or her in the next election. "Clinton/Obama allowed Europe to become a rival under his/her watch" and so on.
I'm sure you all have thought this through much more than Daily Kos has. It's a large issue.
I can see that some Americans might like that, i.e., those who are against US military dispersing to the 4 corners of the world but the implication for the US will be so enormous that I don't see a new administration allowing that to happen so blatantly, hence new adminsitration will be flexible as you rightly say.
So far, there's been nothing in the pronouncements of the 4 current candidates that point in the direction of a weakening US resolve to remain in NATO.
I'd be very very surprised if the next US pres would undermine NATO in the same manner Bush, Gates and Rice have been doing it today.