I think Norway will be the toughest opponent. Norway play well againsy Italy in the friendly and the fact is that Norway rarely lose. Even when they fall a goal behind, or two, Norway has that ability to force it level, usually with that those damn long balls, which will probably used against Spain to the best of tehir ability since not that many players on the Spanish team are very tall.
You could think it will be similar to WC 98, Spain loses the first match to Norway, draws with Yugoslavia, and then thrashed Slovenia, but I think this Spain's year, at least in the group stage, they'll comfortably go through.
Without Raul in attack, it is time or Munitis, Urziaz to shine, especially Munitis has to still has to prove himself further with the national team.