A scrum team can very well be a composed of more-or-less specialized members. This is the situation of almost every team and this can be a good thing IMO, as long as the team can self-organize itself to take advantage of its specialized members.

Please read these two articles for a detailed answer:
 - http://www.scrumalliance.org/articles/324-specialization-and-generalization-in-teams
 - http://www.scrumalliance.org/articles/92-wellformed-teams