Now this is good news! Mathis was a great old-school Bond compadre in the vein of Kerim Bey, Draco, and Columbo. Something very warm about these sort of allies.... Sad that he probably won't make it through this Casino Royale Saga alive
Good news. Liked the character, and liked the unique relationship it added to the Craig-Bond. And if the ubiquitous CIA Agent Wade didn't have to "terminate" in any given film, I don't see why Mathis' days would have to be numbered. In any case, I would hope from what I have seen of him so far that they are not.
Believe me, I hope they don't kill Mathis as well. It's just normal scripting conventions that have me thinking on that line. Right now, the Bond field team(meaning exposed to danger) for the next movie looks like Bond, Felix, and Mathis. Seems like too many people to keep around for the whole movie. Most screenwriters would kill one off along the way to give the tragic spin and make you hate the bad guy more. They're not going to kill Leiter and they're definitely not going to kill Bond, so that leaves us with Mathis.
Also, it seems to fit in with Mathis's character arc. As GC said about his character, Mathis is a good man. Bond obviously doesn't think so at the end of CR, so Mathis will likely spend the most of the next movie trying to convince Bond that he really was on the good side, and that he can trust him. If he were to die in the course of helping Bond out, it would be the ultimate gesture of goodness. That and it could also give Bond some more emotional baggage about how he never trusted this guy until he was about to die.
That would be my 2 cents on it anyway.