Sadly, even if Roberts and Alito turn out as we hope, we still need another vacancy to finally right the Court. The only other hope would be that Roberts and Alito are somehow able to turn Kennedy back from the Dark Side, but his embrace of the living constitution nonsense (as Scalia pointed out in a dissent in the recent case where SCOTUS overturned a 15 yr old precedent on juvenile execution, Kennedy absurdly maintained that the Constitution had somehow changed in the intervening 15 yrs, not that his own views had changed) I think that will be a long shot at best.
I agree with your assertion.
There may be a constitutional legislative way to limit the court's jurisdiction. But, we would need a stronger legislature.