Oh, the tears at that ending - they just had to pull out the stops on that last scene, didn't they? And of course, why not - she certainly deserved it, Sarah Jane, as good as her maker, Elisabeth Sladen, made her.
Maybe they're not going to mention it at all. Maybe Sarah Jane will just fade into the background, and we'll assume that she's still alive, rising Sky and having adventures when we're not looking, and then one day in the far future, maybe when we have a Twelfth Doctor, we'll get word.
I guess the idea of her dying just after adopting Sky is a bit depressing, so maybe they'll just skirt over it for now.
Looks like you called it - RTD wants her to live forever, just like Sarah Jane said she wanted to in Goodbye Sarah Jane.
For just the moment, that's fine with me.