Not that it would be exactly simple to change the livery...
A longshot would be CS being relieved of the sleeper by ScotGov.
I should elaborate by explaining I meant 'simple' as in nothing terribly exciting. Right now, it seems like hype is being built up to produce a news item that will leave us saying "Oh, is that it?"
As I read the other replies, funnily enough I also thought that about CS no longer running things as such. It seems a weird way to go into such a drastic change, but it could happen.
Waiting until 7th March to find out the answer is going to drive me nuts! If it is a terminal change, albeit temporary, then it could lead to some interesting track being covered. Perhaps it's a change of diesel locomotive operations, or it could just be something like extending the Aberdeen portion to Dyce? I really don't know, but I am keen to find out.