I mostly agree with Stephen G. Netrebko has a gorgeous voice and can really act believably on the stage... A real presence that commands attention. She's wonderful in the Russian repertoire and in some Puccini roles (I'd say at least Musetta in La Boheme and Liu in Turandot), but she has some real technical issues when she sings Mozart and bel canto stuff.
When you both 'see and hear' her, you would tend to not notice her vocal fluffs... but when you can only hear (as in listening to a Sirius broadcast or to a CD recording), she can be underwhelming. But then... opera is best appreciated in live theater anyhow.
At any rate, she is, by all accounts, really nice in person. And I think she is a great asset to opera in its effort to recruit new and younger audience. Opera can't just appeal to the older and more traditional generation and not the younger crowd who demand more 'visible' stuff in the performance. It's great that Netrebko and other younger opera stars like DiDonato, Garanca, Ernman, Villazon, Florez, et.al are making opera 'hip' again.
I don't think the other singers begrudge her her success as much as some fans do... She draws more people to the theater, and that increases sales, and that allows the other singers and musicians and staff to be paid more, too. I hope she'll have a long and happy career.