There was quite a bit of talk about this several months back, but the conclusions we came to, based a lot on feedback from those as close to in the know as possible (which isn't saying much, I realize) is the following:

AS will take over ALL N gates and leave all of the D gates, resulting in a net decrease of 1 or 2 gates. To make up for it AS going to push for more effecient and faster turns of aircraft to allow more aircraft in/out of the gates.

1 or 2 of the D gates are currently not leased by AS but are officially common use gates. AS uses these frequently but at a higher per use cost than the leased gates they have in D. Those would continue to remain available to AS if needed.

QX would take over more space in C to relieve the overcrowding of the C2/C3 area they currently have. Not sure what that would mean, regarding how far down QX would extend, but you could assume 1-2 more gates given to QX.

AS has done studies/tests/etc and found that taking the train from C20 - N gates is around 1-2 minutes faster than walking from C20 to D10. The train runs in a loop going C to D/Baggage to N terminal and back to C.

With the economy in the tanks, I highly suspect that some of these plans such as a N terminal overhaul and the shuffling of UA out of N and presumably into D has been slowed.

Speaking of UA - yet another forum (possibly another site even) has speculated that UA and their Star Alliance friends would eventually take over D, so that means US, UA and CO all moving into D.

Currently UA uses 6 gates in N, US has 2 gates in A, CO has I believe 4 in B and AC shares with UA in N. That totals 12 gates which would fill up all 12 of the gates in D.

Ok finally back to the question at hand - if UA is to give up their gates in N and move to D - they would need a place to move the RCC, assuming it stays open, and there really doesn't seem to be a spot to put it, other than in the existing BR. Now if I had my druthers, I'd much prefer to keep the BR where it is, compared to a dungeon down in the basement of N.