I was really impressed by the way he held Spain's midfield together, for the likes of Xavi and Fabregas to venture forward and he playing at the back end of the diamond. And he isn't like the atypical DMC who just breaks thing down. Mind you, Senna can play and from his displays in Euro 2008, he showed that he is comfortable with the ball and often tracked the runs of his more attacking minded team mates and launched several clinical passes for them to ledge unto.
Of course, Monsieur Wenger and over-30 policy. Not everyone is like Dennis Bergkamp who loves the club and is willing to put up with year to year contract extensions (of course no other club would have put up with his fear of flying). However, if Wenger wants to develop a midfield partnership that is tried and tested for the coming campaign, he has to look no further than Spain's recent success for that formula and age should not be a barrier.
But haha..that is just my opinion.