It will take some time for a comprehensive verdict to be made on Dudamel. By "comprehensive", I mean that he will have to guest-conduct the big name orchestras in the US and in Europe, and then and only then can a decent assessment of him be made, both from orchestra players and the press at those venues. One DVD of a Mahler symphony isn't enough to establish him as a significant name to be reckoned with. I've seen him on YouTube, but from what I saw, I too, can't see what all the excitement is about.
One conductor I had high hopes for, who I saw a few years ago at the Washington National Symphony conducting the Tchaikovsky 6th was Mikko Franck, but as of late, I believe illness has sidelined him from his music making. I subsequently purchased his recording of the work, which to most everyone here (including Barry) will sound incredibly slow, particularly the rousing scherzo movement. More to topic, I downloaded Franck's Mahler 5th with the London Philharmonic from the OperaShare site, and it too, is slow as molasses. But despite the slow tempi in both works, Franck exhibits incredible control, and that was visibly evident in the live Tchaikovsky 6th I saw him conduct. He conducts from a chair, but when he wants to build climaxes and get the orchestra to do as he wants them to, he gradually rises from his chair, and that increases the attention level of his players. His beat and conducting is only what is necessary to get the orchestra to do what he wants them to do, but not as minimal as a Reiner or Boehm. Franck was supposed to come to Washington again this past June to conduct the Strauss Eine Alpensinfonie, but for some unknown reason, he was substituted by another conductor substituting Eine Alpensinfonie with Also sprach Zarathustra (again, illness?).