I am an absolutely huge fan of Ralph Feinnes. He's just constantly amazing. I thought his performance in Skyfall was superb. With Mallory, he created a nuanced three dimensional character. In the court room gunfight, I almost whooped with joy when he grabbed a gun and got stuck in - earning our man's respect as he did so (that little wink our man gives him says so much).
When he's appointed M at the end of the film - our man takes the time to actually ask him how he is! This shows that our man likes and respects him and will be happy to take orders from him in future. I really want to see this excellent character developed more.
When you've got two actors like Daniel Craig and Ralph Fiennes in the same movie(s), you cannot squander that potential. I don't want to see Mallory just give our man his mission at the start and debrief him at the end. I also don't want to see Mallory be a repeat of previous Ms where he is constantly berating our man. I'd like to see this guy cover up Bond's mistakes and watch his back. I want him to be that kind of boss.
I also want to see him in on the action. In the pre-credits sequence it would be cool if Bond is in a spot of bother and radios in for backup. Yet, rather than another 00 agent or someone else show up - Mallory himself appears and says something to our man along the lines of "Sorry old chap, everyone else was busy - you'll have to make do with me" and see them fight their way out of the $#!+ together. Then, at the end of the movie when everything is REALLY kicking off, Mallory once again jumps into the fray to back our man up.
There's a hint of a friendship being formed in Skyfall and I would LOVE to see that thread explored and fleshed out as this phase in the movie series develops.
Either way, Feinnes is a boss actor - and no matter what they do with him it will be awesome. Just as long as they don't make the mistake of wasting him.