If Snape still want to play Dumbles for a fool, he'll have to inform him that Volemort is back, else D.'s trust in him will vanish right away if he learns that little critical piece of information from another source. So, chances are that Neville will spend some time at the Order's headquarters (wherever it will be) this summer for some influencing. I have fun thinking about Neville directly asking Dumbledore if he was the one who put his name in the Goblet... It's so amusing thinking about how the old man's reaction to that will be.
Or Snape gets to be offed next book if he's really hiding it from Dumbledore. I doubt the trinity will miss that chance once they have proof of his true allegiance.