One can say roughly the same thing on school choice, where we will eventually (I believe) end up with parental choice, and market solutions to the health care funding dilemma, where Bush again defined the correct solution but didn't have the votes in Congress to get over the hump. Bush will be remembered with respect as having helped mainstream constructive reform, though ahead of his time.
We will eventually win the war on terror, but it now looks like some thousands more Americans -- and we'll be lucky if the toll is only in the four digits -- will have to die before the left sobers up. Bush will be lauded by the postwar historians, and todays crop of leftists will be viewed with contempt.
Bush has performed personally with decency, grace, integrity, and humility. The BDS democrats will be seen by historians as, again, contemptible.
Bush let Congress run away with spending and will be fairly criticized for that. He will also be open to justifiable criticism on immigration, but I very much doubt that our Spanish speaking successors will care very much about that, as we will be majority hispanic before 2075. Any English speaking holdouts will be like the Gaelic remnants in Britain today.
I believe that President Bush tried too hard to reach out to the entire country and got no respect from either side. He was just too dam* nice.