Looks good, but not as good as An American Werewolf in London's transformation. It just doesn't look as natural, too shiny or something.
Funny though, I thought most of the transformations in Underworld were pretty good, and those were CG - and with 1/4 the budget of the Wolfman. I think the trick they did well was doing it in sudden, violent jerks, rather than a smoother look - not to mention darker lighting. However, the film still isn't coming out for like 6 months, so I'll hold off on final judgement for the transformation scenes until I see it in the theatre.
I'm quite looking forward to this one, as I love werewolf films... But the director of it makes me leery. It's Joe Johnston, who did The Rocketeer, the Pagemaster, Hidalgo, and Jurassic Park III. None of these films are really BAD, but they're all just kind of barely above mediocre. They all feel like they're missing a certain spark of energy, like something just didn't quite gel right.
But, at least they picked a director obviously very used to working on effects heavy films.