Has just been released in the UK under the name "Temeraire". Just read it - very interesting, nice work and quite authentic sounding to say it's an American author.
Some of the reviewers have pointed out that it's similar to Susannah Clarke's "Jonathan Strange and Mr Norrell", in that it consists of a fantastical element participating in the Napoleonic Wars without actually affecting the outcome. Although [spoilers] Nelson does not die at Trafalgar, merely being seriously wounded and having all his medals welded to his flesh from being melted by dragonfire.
And the end, in which the French attempt a sort of Operation Sealion by air (which, of course, fails thanks to the Few, sort of) was very nice. I hope there's a follow up, or at least similar work by the same author.
My only real issues with it was that in parts it was kind of reminiscent of the Anne McCaffrey female wankfest thing with dragons, almost as bad as unicorns...although at least in this case the dragons were bloodthirsty by nature, more realistically.