The beauty of tournament soccer is that there is no way of knowing what might happen in a single game. Can Portugal beat Spain? Of course. Can Spain beat Portugal? Of course.
Spain will want to limit the ball supply to Ronaldo, and they will do it by keeping it away from him and the Portuguese. It should be an apotheosis of tika-taka, and there'll be more people hating the Spaniards for killing the game and preventing the singular (lazy, selfish) genius of Ronaldo from expressing himself. If Spain win, they might extinguish Ronaldo's last chance to accomplish anything in a major tournament. If Portugal win, that might spell the end of the international tika-taka.
In the other game, it is hard for me to see how Germany can lose. But then, England nearly got by Italy. The Germans will not give time to Pirlo to dance in the midfield, as the English, idiotically, did.
That is to say, Germany-Spain in the finals, as expected.
But then, who knows?