Lists of that kind are always fascinating, but for our present purposes we need to remember that they're heavily weighted in favour of seniority and therefore aren't fully representative of the present day. Blomstedt belongs stylistically to the era of Keilberth or even Weingartner; in no way is he representative of contemporary conducting practices. Serebrier was Stokowoski's star pupil; he has too much sense to imitate his master, but every bar of his conducting (and composing) is steeped in the ambience of that world. Slatkin, likewise, is redolent of the time when New Music was Copland's ballets and his father was playing in the Hollywood Quartet. The vast majority of present-day conductors are living in a different realm--I'd almost say, on a different planet.

Indeed the inherent assumption behind such lists--that the "greatest" or "top" people can be sought, to a large extent, among the most senior ones--itself belongs to the past era. When I was young, there did indeed tend to be a belief that conductors got better with age, and produced their very best work after the age of 70 or 80 (see the old Penguin Record Guides passim)--even though many glaring cases to the contrary were conspicuous in full view of the public (Toscanini, Ormandy...). Today the real "top" stars, the ones promoted most actively by recording companies, increasingly tend to be in their teens or twenties. By the age of 40, they're no longer news and are struggling to get contracts even with the most marginal recording companies.

I don't say that such things are right or wrong; I merely note a couple of trends.