I think there will be extensive resources devoted to it, but not as much as if there were, say, 10 or 15 years until Doomsday. After the first generation, as people grow up with the knowledge that this thing is coming, I think it'll become something people just live with, like the threat of nuclear war was during the Cold War-- it's only when it becomes visible in the night sky that the real scramble will start, as everyone and his uncle tries to prove that they're necessary for the survival of the offworld program, or just try to bribe or seduce or blackmail or force their way in through means fair, foul, and fouler.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary