I always think it's odd how everyone always says Meisel has no distinctive style. I mean, in most cases I can look at something straight away and recognise it as his. Plus I'd like to see Klein, I&V, Mert&Marcus or even somebody like Roversi try and take on the mammoth challenge of doing every single Vogue Italia cover - it would essentially just be the same thing again and again. Meisel occasionally revisits past themes, but is then accused of being unoriginal, uninispired or looking too much to the past.
I think his individual style can be seen more in campaigns than editorials, maybe because the number is less - Alberta Ferretti or Prada campaigns, for example, always have that distinctive Meisel feel.
As BerlinRocks said; the best, most important feature of Meisel's work is his ability to manipulate influences and work with them to make them his own - that makes him a great imitator perhaps, but I don't think that necessarily takes away from his importance as a photographer. I think he seems to understand that he works in fashion, and not "high" art - he clearly loves clothes and models especially, and is not as pretentious as say I&V IMO.
Finally, it seems to me that his true "signature" of sorts lies in his relationships with his models - no other photograper working today can time and time again bring out the very best of his subjects. There is this wonderful, organic nature to how his bond with his favourite models (Linda, Karen, Guinevere, Elise, Stam, Sasha and so on and so forth) develops. It makes his work have a personal, almost auto-biographical quality that's a joy to track. That's what makes this thread so interesting!