Definitely! If wewe compared season 1-3 to 4-7, there is such a difference. He's still that person he was, but he's so much zaidi mature now. As much as I hate to say it, I think part of it was down to Jeanne. Even though he was pretending to be somebody else, it rubbed off on him somewhat and he matured as a result.
He totally has but their are flickers of the younger Tony still in his personality. This could be down to age but I think that Ziva has had a huge influence on the way he is- its so obvious that they need eachother and when one is gone they struggle!! especially tony (see the episode entitled 'Aliyah' it shows majorly when Tony tries to defend her) Also the jokes and references made to McGee are a lot zaidi grown up and mature since the introduction of Timmy!!! Though the childish jokes are still there!!!